读课文《鲸》，圈出句子中的错别字，并改正。鲸的寿命很常，一班可以活几十年到一百年。

在平面四边形ABCD中，∠A=∠B=∠C=75°，BC=2，则AB的取值范围是____  .   

材料一：分工、水利特别是蒸汽机的利用、机器的应用，这就是从18世纪中叶起，工业用来震撼旧世界基础的三个伟大杠杆。

——恩格斯《英国工人阶级状况》

材料二：因为在最先使用机器的地方，机器就把大批手工工人抛到街头上去。

——马克思《雇佣劳动资本》

材料三：蒸汽机教我们把热变成机械运动，而电的应用将为我们开辟一条道路。

——恩格斯《致爱·伯恩斯坦》

阅读短文，判断正误。用“正确”或“错误”表示。

Penguins are good swimmers, and they are very good at swimming in the sea. They can dive much deeper than people. Some people can dive about 180 metres, but most people can only dive about 30 metres. Penguins can dive 500 metres. That is a long way down! Do you know the TV Tower in Shanghai? That is 468 metres high.

 Penguins can hold their breath much longer than people.Some people can hold their breath for about five minutes, but most people can only hold their breath for one or two minutes. Penguins can hold their breath for 20 minutes.

Many whales can hold their breath longer than penguins. Some whales can hold their breath for about two hours!