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，又略呈圆形，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。”