自然地理类 知识点题库

    Australia is nearly 7.7 million square kilometres. It's the sixth largest country after Russia, Canada, China, the United States and Brazil.

    There are rainforests and large plains in the north, snowfields in the southeast, desert in the centre and croplands in the east, south and southwest. About one third of the country lies in the tropics (热带地区). Australia has a coastline of 34,218 km. If it were possible to drive non-stop along the whole coast at 60 km/h, it would take about 24 days to complete the trip.

    Australia is on the world's smallest continent (洲) and the sixth largest country being equal (相等的) to the USA without Alaska, The continent is one of the oldest lands. And it is the flattest of the continents.

    The population of Australia is more than 20 million. It is one of the world's most urbanized countries, with about 70% of the population living in the ten largest cities. Most of the population is concentrated (集中) along the eastern seaboard and the southeastern corner of the continent.

Our world is becoming hotter and hotter because of climate change. Some scientists worry that the hot weather will the crops around the world.

Scientists say about one of the world's plants will die out over the next 20 to 30 years. That's it's important to build a library of wild plants.

The programme will include(包含) 23 crops, such as bananas, beans, potatoes, rice, wheat and so on. The work will 10 years. The first trip will start next year, and scientists will keep the plants in a of places around the world.

    In England, people often talk about the weather because they can experience (经历) four seasons in one day. In the morning the weather is warm just like in spring. An hour later black clouds come and then it rains hard. The weather gets a little cold. In the late afternoon the sky will be sunny, the sun will begin to shine, and it will be summer at this time of a day.

    In England,               , or have winter in summer. So in winter they can swim sometimes, and in summer sometimes they should take warm clothes.

    When you go to England, you will see that some English people usually take an umbrella or a raincoat with them in the sunny morning, but you should not laugh at them.

    If you don't take an umbrella or a raincoat, you will regret (遗憾) later in the day.

Wonder of the Natural World

When I arrived, it was early morning and it was raining. I looked to the east—the sky was becoming grey. I got out of the car, went through a gate and walked along a dark path. There was nothing to see, but I knew it was there.

After about a mile, a stranger appeared beside the path. "Am I going the right way?' I asked. He knew where I was going. "Yes,' he replied. "you'll get there in five minutes.' Finally, I came to some rocks and stopped. I looked over them, but it was silent and there was no sign of it.

Suddenly, the rain stopped and the clouds cleared. The sun rose behind me and shone on the rocks. Far below me, the ground fell away and down to a river. I was looking across one of the wonders of the natural world –the Grand Canyon.

I looked down to the Colorado River, a silver stream nearly one mile below me. If you put the two tallest buildings in the world on top of each other at the bottom of the canyon, they still would not reach the top. Then I looked across to the other side of the canyon. It was about fifteen miles away, maybe more. Finally, I looked to my left and to my right, and on both sides the canyon went far away for more than 200 miles. The Grand Canyon was not just big. It was huge!

I remained by the canyon for about half an hour, and I asked myself, "Is the Grand Canyon the greatest wonder of the natural world?' I certainly know the answer. What do you think?

As many as 10 of the 17 kinds of penguins (企鹅) may be in danger of disappearing. The number of penguins have decreased (减少) by 30% since 1987.

Penguins are black and white birds that live in the southern part of the world. They are common in South America, New Zealand, Australia and South Africa. Mary live near cold waters. But some live near warm waters in Galapagos Islands. Penguins cannot fly, but they are fine swimmers. Penguins eat fish and krill(磷虾).

The warming of the earth is the decrease in penguin populations. The heating of the air has caused ocean waters to become warmer. Higher water temperatures have reduced the supply of fish and krill. Some years later these birds are completely unable to reproduce(繁殖). Besides, many adult penguins die of hunger.

Widespread(广泛的) fishing, exploration for oil and oil leaks(漏) also make penguins be in danger. Poisonous organisms(生物) in ocean water are another danger. Penguins also have their enemies, including wild dogs, sharks, seals and sea lions.

News about penguins is not all bad, however. Several years ago, oil leaking from a ship hurt 40% of the penguins in South Africa. The penguins became covered with oil. But thousands of people helped clean and treat the birds well. Then they returned the penguins to the wild. Now these South African penguins are reproducing in higher numbers than before the oil leaking.

When your town has winter, the earth's axis(轴) is pointing away from the sun. Your town doesn't get as much light or heat from the sun. The days are shorter and colder.

Winter and summer happen because the earth is tilted(倾斜) as it revolves around the sun. The northern end of the earth's axis points towards the sun in summer. You have more hours of light in summer. Your part of the earth is towards the sun for more hours each day. When the part of the earth where you live is towards the sun, you have hotter days. In winter, when your part of the earth points away from the sun, you have colder days.

You have learned about winter and summer. There are two more seasons in the year. One comes after winter and before summer. The other season comes after summer and before winter. Can you name them? That's right. Spring comes between winter and summer and autumn comes after summer but before winter.

The four seasons are spring, summer, autumn and winter. Spring and autumn are apposite seasons. Which season do you like best?

You have thought about the four seasons of the year. Each season is different. The seasons are made by the northern end of the axis pointing towards or away from the sun.

Your part of the world gets more heat from the sun when the northern end of the axis points to the sun. When the axis points away from the sun, you get less heat. Now you know why winter is colder than summer. The axis is pointing away from the sun in winter. It is pointing towards the sun in summer.

A big snow hit our hometown last winter. The news report said that it had been the m serious snow disaster in the past 20 years. The snow made travelling h . And it also caused some traffic a.

Too much snow might be a disaster. But children might like the snow. They had some days o because of the snowy weather. Many of my classmates felt h. "It was a wonderful time b we didn't have to go to school!"Tommy said. They enjoyed having a snowball fight and they had great f making snowmen together.

"Snow c everything and turned the world into a white one. It was much h than last year, " said one of them. "We had plenty of snow to make big snowmen!"

 "If the snow didn't make t for traffic, we would hope it would never stop!"said the children.

Huge Waves Destroying Arctic Ice Faster than Expected

Ice covers much of the Arctic Ocean. Some pieces of ice are huge, like moving islands. As temperatures have increased , however, some of the ice has begun to disappear. Scientists have discovered huge waves in the arctic waters.

The waves were discovered by accident in May, 2010. Scientist Aleksey Marchenko and his students set out on a trip. They wanted to study the icy waters.

The ship travelled east and stopped next to a large block of ice around 50 miles from the small island of Hopen. Marchenko prepared to lead his students out onto the ice.

"We were ready to go but when I went out, I discovered many cracks around," he remembers.

He decided to move the ship deeper into the ice to keep safe. The farther in they went, he thought, the harder the ice would become. As they pushed forward, however, the ship experienced small waves, and then bigger ones. Soon, the waves broke up the ice around the ship into thousands of smaller pieces.

Within an hour, Marchenko and his team saw a wave that was about 13 feet high. The ship's navigation system finally recorded the largest waves. They were more than 20 feet in height. The waves were so strong that they forced huge pieces of ice to jump up and down, breaking the ice into smaller pieces within just one hour. Scientists had never imagined that the process could happen so fast. The waves in these areas used to be small.

The speed and force of the huge waves there makes it impossible to know in advance when they are coming. That could be dangerous for navigators and local communities who are unprepared for huge waved or depend on sea ice to protect them. Wildlife like polar bears that depend on sea ice to live is also in danger.

Some scientists think people will soon see even bigger waves in icy waters. As waves break up ice, seas will be more open, waves will be stronger. There are stormy times ahead.

    Some people say they can know what the weather will be like from animals. They believe that birds, chickens and frogs can tell the weather.

    When they see birds fly high out to the sea, they know it is a nice day, because birds won't fly out when it's rainy. When the weather becomes bad, birds will come back to the beach. A big wind may come with a rain. Birds do not like to fly in a big wind. They may sit in a tree while rain is coming. It's a cloudy day. The rain is coming. Chickens aren't quiet, and they are running here and there. Frogs are making a big noise in the pool. If it is a nice day, the frogs will come out of the water.

People in the city often travel by car, bus or bike. People near the sea travel by ship or boat. People in the snowy north have to use sleds. How do people often travel in the desert? Yes! Camels who are large animals living in dry areas can help.

Camels' body structure is different. Camels are very strong animals with wide, padded feet. They have thick leathery pads on their knees and chest. Camels have nostrils that can open and close, protecting them from the desert environment. Bushy eyebrows and two rows of long eyelashes protect their eyes from sand. Their mouth is extremely tough, allowing camels to eat thorny desert plants. Their widened feet help them move without sinking into the sand. Their thick coats stop sunlight, and also protect them from the heat from desert sand. Their long legs help keep them further from the hot ground.

Another is camels' adaptability. Camels are quite well-adapted to long travelling. Camels can go without food and water for 3 to 4 days. There are two kinds of camels. One is the Arabian camel with a hump. The other is the Bactrian camel with two humps. People commonly believe camels store water in their humps. In fact, the humps are actually full of fat, which gives camels power when they go through the desert. Camels are also quite well-adapted to their environment. When weather changes, camels can change their own body temperature, which stops sweating and water loss. They may not sweat at all during the day.

Because of these above, camels can carry people or things through the hot, dry deserts of the world. They are sometimes called "ships of the desert".

However, camels are in danger! The number of camels is becoming smaller for many reasons...

It's December. It is snowing and the weather is(real) cold in the north of China. You can see many (child) playing with snow. Some of them (make) snowmen. Some(be) skating on the river, because it's so cold that the water in the river freezes(结冰). It's a white world. How beautiful! But in Australia now, the weather is hot. Many people go (swim) in the sea. They are having a good time. Jim and his friends  (play) soccer near the sea. The(sun) weather is really cool. They want(swim) after playing soccer.

 are they swimming in December? That is winter, isn't it? Yes, it is in China. But it isn't in Australia.  China and Australia have different seasons in a year.

There are four seasons(季节) in China. Spring comes first. in1parts of China, spring is usually very2. It usually comes in February3March. Summer comes4spring. Usually it's very5in summer. And the hottest month is July. Autumn6from August and lasts(持续)7three months. The weather can be cool in autumn. Winter is the8season of the year. It lasts from9to January, and it's very cold. You can go skating. It's an interesting10.So it's best to come to China in spring or autumn.

From far out in space, Earth looks like a blue ball. Since water covers three-fourths of the Earth's surface, blue is the color we see most. The continents (陆地）look brown, like small islands floating in the huge, blue sea. White clouds cover around the Earth like a light blanket（毯子）. The Earth is shaped like a sphere, or a ball. It is 25,000 miles around! It would take more than a year to walk around the whole planet. A spaceship can fly around the widest part of the sphere in only 90 minutes.

Even though spaceships have traveled to the Moon, people cannot visit the Moon without special suits. The Moon has no air or water. Plants and animals can't live there either. Astronauts first landed on the Moon in 1969. After that, there were six more trips to the Moon. They brought back Moon rocks, which scientists are still studying. There are holes, or craters(火山口), all over the Moon's surface. Scientists believe that meteorites（陨石）smashed into the Moon millions of years ago and formed the craters.

The Sun is the closest star to Earth. A star is a hot ball of burning gas. The Sun looks very big because it is so close. But the Sun is just a medium-sized star. Billions of far-away stars are much bigger than our Sun. The burning gases from the Sun are so hot that they warm the Earth from 93 million miles away! Even though the Sun is always shining, the night here on Earth is dark. That's because the Earth rotates, or turns around, every 24 hours. During the day, the Earth faces the Sun. Then we see light. During the night, the Earth turns away from the Sun. Then it faces the darkness of space.

Each day we learn more about the Earth, the Moon and the Sun.

Welcome to the Eiffel Tower! It was built by Gustave Eiffel, a famous engineer. The tower was finished in 1889. It is made of iron. There are about 18,038 different altogether. The height of the tower is about 324 metres. It is the tallest building in Paris.

At , some people did not like the tower. They said that it was very ugly. But after a few years, it became very . The tower has which go up to the top. There is a very good view of Paris there. On a clear day, you can see for more than 30 miles. If you don't want to go by lift, you can walk up the , but remember that there are more than l,000 steps up to the top.

The tower is repaired every years. It is in colour. About 45 tonnes (吨) of paint are needed to repaint it.

A new study has found that elephant seals have to work very hard to stay fat. It's the most complete study of the feeding behavior*of northern elephant seals.

Scientists paid special attention to the female* elephant seals during difficult two-month trips, in the northeastern Pacific Ocan. Researchers studied 48female elephant seals from Afo Nuevo State Park in California as they traveled large ocean distances. Their trip was around 6, 000 kilometers.

Scientists based their findings on data collected in 2011 and 2018. They used three small devices*.

One device, attached*under the jaw, counted the number of times the seals fed and measured their depth. A second satellite-linked device，attached to the head，followed the seals' ocean movements. The third device was a "smart" video camera and another depth sensor. It was also attached to the head.

The seals were found to spend about 20 hours every day - and sometimes a full 24 hours – in continuous deep-diving to feed on fish. They fed 1, 000 to 2, 000 times daily to stay fat, necessary for warmth in the cold waters. They eat huge amounts of small fish, but it is difficult for them to catch enough small fish to meet the energy needs of their large bodies. 

Taiki Adachi of the University of St Andrews in Scotland led the study, said about the female elephant seals:

"They keep diving, for long periods of time, with only a few minutes breathing at the surface. "Adachi noted that the seals do not come back to land for their two-month trip. "According to our record of foraging, their time for sleeping is less than 20 percent of the day, "he added. 

Northern elephant seals give birth in California and Baja California, usually on offshore islands, from December to March. During their mating season, they do not eat. During this period they lose about a third of their body weight.

①Swifts live mostly in the air. These small birds are among the fastest animals on Earth. In fact, swifts can go two or three days without touching the ground! To get used to life in the sky, swifts use their speed and the saliva in their mouths.

②Swifts can fly faster than 100 miles per hour. That's because their wings are like boomerangs. This shape of the wings helps them to fly much faster. They can also move one wing faster than the other, which allows them to make sharp turns without slowing down. Making fast, sharp turns helps swifts catching flying bugs to eat.

③The saliva helps swifts catch bugs to feed their young. It is sticky, like glue. Swifts often fly into clouds of bugs such as mosquitoes and open their wide mouths to catch as many insects as they can. The bird collects insects in its mouth graduallyand holds the insects in a sticky ball of saliva. One food ball can contain nearly 1,000 bugs.

④Swifts also use their saliva as glue to build their nests. The birds catch feathers in the air and stick the feathers together to build a strong nest on the side of a cliffor building. Swifts' short feet are not good for walking or standing on land for long. But their sharp claws allow them to stick to rocks and walls so they can take a brief rest before returning their lives in the sky.

There are about 250 kinds of turtles. Most turtles live near fresh water. However, land turtles, also known as tortoises, do not swim at all. Sea turtles live nearly their whole lives in salt water.

Tortoises

Tortoises are slow. They have short, thick back legs. Their front legs are very good for digging. Many tortoises can pull their heads, legs, and tails inside their shells. They quickly do so at any sign of danger. Their strong shells can protect them. Unlike most other turtles, tortoises eat only plants. Tortoises hatch from eggs. The mother tortoise digs a hole, lays some eggs, and covers them with earth. When the baby tortoises hatch, they must dig their way out of the hole. The largest tortoises can grow to four feet long. They may weigh up to 600 pounds.

Sea Turtles

Like tortoises, sea turtles lay their eggs on land. The mother turtle comes out of the ocean onto the beach. She digs a hole, lays her eggs, and returns to the sea. When the baby turtles hatch, they head straight for the water. Sea turtles can swim very fast. They use their front legs like wings to "fly" through the water. Although most turtles can pull their heads and legs inside their shells, sea turtles cannot. The green sea turtle eats only plants. Other sea turtles eat both plants and animals. The largest of all sea turtles can weigh over 1,000 pounds.

Get to know different kinds of turtles and compare them.

When will tortoises pull their heads and legs inside the shells?

People started to study (研究)the weather very early. They used many different ways. Some are still useful. Let's have a look!

Watch the sky (天空).

Different kinds of clouds mean (意味着) different weather．How the clouds move also means different weather. Usually. white and high clouds mean good weather. Dark and low (低的) clouds mean bad weather.

Your parents may tell you, "Red sky at night, don't go out. Red sky in the morning, walk for a long time. "Well, this is quite right.

Watch animals.

Look at the birds. Usually, they fly very high in the sky. And this means good weather.

And this means bad weather. Birds also get very quiet before it rains.

Look at the turtles (乌龟). You can see them on the road 1 to 2 days before a rain.

Sometimes, they will stay together and keep quiet, because bad weather is on the way.