根据短文内容，判断句子正误

There's not enough clean water for everyone in the world. Some people even (甚至) lose their lives because of lack (缺乏) of water. In a lot of countries, people have to cut down trees for a living. So there's nothing to keep water from running away. Then there are more and more floods (洪水) and droughts (干旱). People also pollute the land and the river. Polluted water can make people sick. Then what can we do to help?

Don't waste (浪费) water! Take short showers, don't leave the tap running and try to reuse water.

Stop water pollution. Use natural (天然的) cleaning products instead of (而不是) toxic (有毒的) ones in your home. Planting more trees and flowers can also make a difference.

Don't litter. Always pick up your rubbish, especially (尤其) when you are at the beach, lake, or river. We should collect and sort (分类) it for recycling.

a×b=c，当a一定时，和成正比例关系：当b一定时，和成正比例关系。

他们是我的叔叔和阿姨。

工程队修一条路，甲队单独修12天能修完，乙队单独修8天能修完，如果两队合作一起修，修了全长的 ，已经修了多少天？

是我国著名的活化石植物。

一根铁丝长 m，截去 ， 还剩下m：若截去 m，则还剩下。

一批纺织品的合格率是98%，300件产品中有（   ）件不合格。

选出不同类的单词（）

混凝土是用水泥、沙子和石子拌制而成的。水泥、沙子和石子的比是2：3：5，要拌制60吨的混凝土需要沙子多少吨，石子多少吨?

Would you like to _________ apple juice?

甲、乙两数的比是4：5，乙比甲多。（     ）

圆柱的体积是圆锥的体积的3倍，圆柱和圆锥一定等底等高。（    ）

（    )被誉为19世纪自然科学的三大发现之一。

比一比，算一算。

半径是5厘米的圆，它的周长和面积相等。

在比例尺1：3000000的地图上，甲、乙两地的距离是8cm，一辆客车和一辆货车同时从两地相对开出，经过3小时相遇，客车每小时行44km，货车每小时行km．

根据上下文，从方框内选择适当的句子补全对话。

A. Yes, there were. B. The mountains are wonderful. The trees are high. And the sky is nice and clean. C. I went to Hunan with my parents. D. Did you take any photos? E. How did you get there?

Linda: Hello. David. Where did you go during your school holiday?

David: Hello. Linda. . And we went to visit Zhangjiajie.

Linda: Great!

David: We went there by plane.

Linda: Can you tell me more about it?

David: Yes, it's beautiful.

Linda: Were there many people there?

David:

Linda: Did you have a good time?

David: Yes. I won't forget it.

Linda:

David: Yes, I did. I can show you some tomorrow.

Linda: That's great!

The oranges are falling down the (楼梯).

绿水青山就是金山银山．在一座荒山上种1.2万棵树，如果由一队单独种，需要8天完成，如果由二队单独种需要10天完成．现在两队合种，4天能种完吗？

We can be pen friends. （升调/ 降调/ 先升后降）