A survey indicates the _____ of men to women in the population has changed in recent years.
He made up his mind to devote his life the river polluted.
Many people think that it is making such an experiment.
One day I a newspaper article about one in six European mammal species threatened with extinction.
We can catch sight of millions of stars in space.
第一节:单项填空(共15小题;每小题1分,满分15分) 从A、B、C、D四个选项中,选出可以填入空白处的最佳选项。 --- How long are you staying? --- I don’t know. . A. That’s OK. B. It depends. C. I am going. D. It’s doesn’t matter.