电化学腐蚀的条件是（）。

A．氮气

B．潮气

C．二氧化碳

根据汉语意思完成句子，每空一词。

1．绿色长城会阻止风把泥土吹走。

      The Great Green Wall _____ the wind _____ blowing the earth away.

2．这部电影和那部电影一样有趣。

      This film is _____ _____ _____ that one.

3．他的父母告诉他不要吃太多的快餐。

      His parents told him not to eat _____ _____ fast food.

4．我们应该一直竭尽全力。

      We should _____ _____ _____ all the time.

5．提起约翰，上周我看见他的妹妹了。

      _____ _____ John,I saw his sister last week.