城市化发展最早和首先出现逆城市化现象的国家是(　　）

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!

 在三个相同的烧杯里装入质量相等的甲、乙、丙三种不同的液体，把一支装有适量铁砂的平底试管先后放入这三个烧杯中，静止后如图所示．下列说法正确的是（　　）

在人类起源和发展的漫长历程中，森林古猿下地生活的原因是（　　）

新型胃动力药吗丁啉的每个分子中含223个碳原子、24个氢原子、1个氯原子、5个氮原子、2个氧原子，由此可判断吗丁啉组成中含有的元素种类是（   ）