If parents never expect their children to be helpful at home,they are sure_.If parents never expect their children to be helpful at home,they are sure___. A.not B.not to C.not to be D.not to be that 为什么选C不选B?

If parents never expect their children to be helpful at home,they are sure_.If parents never expect their children to be helpful at home,they are sure___. A.not B.not to C.not to be D.not to be that 为什么选C不选B?
If parents never expect their children to be helpful at home,they are sure_.
If parents never expect their
children to be helpful at
home,they are sure___.
A.not B.not to
C.not to be D.not to be that
为什么选C不选B?

If parents never expect their children to be helpful at home,they are sure_.If parents never expect their children to be helpful at home,they are sure___. A.not B.not to C.not to be D.not to be that 为什么选C不选B?
If parents never expect their children to be helpful at home,they are sure___.
如果父母不指望孩子们在家勤快些,他们就必定不会（在家勤快）
这里其实是 not to be (helpful at home) 须与前面对应.

选B局子里就没有动词了，用be动词顶替

和be helpful 对应 的