—How was they discovered the entrance to the underground palace?—Totally by chance.A. it

问题补充：

—How was they discovered the entrance to the underground palace?

—Totally by chance.

A. it that

B. he that

C. it which

D. it

答案：

解析：这题考查强调句的特殊问句：疑问词+is/was it+that….选A，句意是：他们是怎么发现地下宫殿的入口的？--完全是偶然的。选A。