Scientists believe Native Americans arrived by crossing the land bridge that connected Sib

问题补充：

Scientists believe Native Americans arrived by crossing the land bridge that connected Siberia and more than 10 000 years ago.

A. this is Alaska

B. Alaska is now

C. is now Alaska

D. what is now Alaska

答案：

A. this is Alaska

B. Alaska is now

C. is now Alaska

(答案→)D. what is now Alaska

解析：宾语从句what is now Alaska“现在叫阿拉斯加的地方”。what引导的从句含有“所……的（东西）”之意。