.
Over the past decades, sea ice _____ in the Arctic as a result of global warming.
| A．had decreased | B．decreased | C．has been decreasing | D．is decreasing |
Many people think that it is making such an experiment.
| A．worthwhile | B．worth | C．worthy | D．valuable |
One day I a newspaper article about one in six European mammal species threatened with extinction.
| A．came at | B．came across | C．came about | D．came after |
We can catch sight of millions of stars in space.
| A．/, the | B．the, / | C．/, / | D．a , the |
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.
In China, a number of peopleEnglish now, and the numbergrowing year after year.
| A．studies, is | B．are studying, is | C．is studying, is | D．is studying, are |