We were swimming in the lake _____ suddenly the storm started.
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.