这三个英语选择题怎么选呀?为什么?

这三个英语选择题怎么选呀?为什么?
1.Although he refused to act on my suggestion,he had to admit that ______ what I said.
A.there was something in B.it was something in
C.there was something as D.it was something as
2.I saw Bill sitting in a front seat ______ at the speaker with the strangest look.
A.staring B.stares
C.stared D.stare
3 The children,______,were allowed to leave the table.
A.to eat their fill B.had eaten the fill
C.having eaten their fill D.have been eaten their fill