As a child, I was _________to keep quiet when my parents were discussing something, while parents nowadays often ask for their children’s opinions.

When he was asked suddenly about the matter ,he couldn’t_____an answer at once.

As a senior high student, you should 　　your energy on how to master the skills of learning.

None of us expected Lily to _____ at the party. We thought she was still in Beijing. 

 —Do you know where my blue coat is ?—Don’t bother to look for it. I’m sure it will _______ some day.