__was a disappointment to us that Tony didn't come to the party.

问题描述:

__was a disappointment to us that Tony didn't come to the party.
A.That.B.As C.It.D.This
(具体解析)

C
it 做形式主语,that Tony didn't come to the party是真正主语
托尼没来参加派对真让大家失望