问题
单项选择题
The large size and roughly circular shape of the Pacific made some scientists think that it ()a hole left when the moon separated from the earth.
A. used to be
B. would have been
C. might have been
D. should have been
答案
参考答案：C
解析：
根据句子的意思，it might have been a hole只是一种猜测，其他几个选项都不符合要表达的这种逻辑意义。题句意为：“太平洋浩瀚巨大，又大致呈圆形，这使得某些科学家认为它也许是月球脱离地球时留下的一个大坑。”