①山脉、②山脉 ③平原
④平原 ⑦河、⑨河
Can dolphins (海豚) talk? Maybe they can not talk with words, but they can talk with sounds. They show their feelings with sounds. Dolphins travel in a group. We call a group of fish a "school". They do not study, but they travel together. Dolphins are mammals (哺乳动物), not fish, but they swim together like fish in a school. Dolphins talk to the other dolphins in the school. They give information to the others. They talk when they are happy, sad or afraid. They say "welcome" when a dolphin comes back to the school. They talk when they play.
They make some sounds above water. They make many more sounds under water. People cannot hear these sounds because they are very, very high. Scientists make tapes of the sounds and study them. Sometimes people catch dolphins for a large aquarium (水族宫). People can watch dolphins in a show. Dolphins do not like to be away from their school in an aquarium. They are sad and lonely. There are many stories about dolphins. They help people. Sometimes they save somebody's life. Dolphins' meat is good, but people do not like to kill them. They say that dolphins bring good luck. Many people believe this.
1)要点:动物的外貌、习性及特点。
2)词数:50左右。
①热带草原气候分布广
②全年降水少,蒸发量大
③热带沙漠气候面积大
④气温年较差大,年均温低
A.①② B.②③ C.③④ D.①④
沙特阿拉伯是西亚沙漠面积最大的国家,人口主要分布在波斯湾沿岸地带。该国在北部的沙漠地区大力发展种植业,采用先进的喷灌设备,以地下水源为轴心,在一个个圆形区域内进行灌溉,形成了片片圆形水稻田。但粮食的大面积种植会造成水土流失等问题。
错误 1:;错误 2:。