主语从句的题,

问题描述:

主语从句的题,
15._____ is a pity that he should feel so upset.D
A.What B.That C.He D.It
16._____ a spoonful of soil can tell us so much about the structure and early
history of the moon.
A.Remarkable B.Quite remarkably C
C.It is remarkable that D.It is remarkable
麻烦给个详细的点的解析,比如第一题为什么选D,为什么不选别的.

15.D 16.C
这两题类型是一样的.It is.that.
that引导的是主语从句(真正意义上的主语),而It只是形式主语