49. Antarctic () we know very little is covered with thick ice all the year round. A. which
B. about which C. that D. where
满分：2 分 正确答案:B
50. — Thank you for everything you’ve done for me during my stay here.— (). Give my best wishes to your parents. A. My pleasure.
B. I don’t think so. C. Very well D. Don’t worry. 满分：2 分 正确答案:A