He won’t want to eat it unless he’s really hungry, in ______ case he’ll eat almost anything．

Is this the reason ______ at the meeting for his carelessness in his work?

Would you be kind enough to help the boy _____ Chinese is really hard to learn?

We can never forget the days _______the two astronauts in spaceship worked together and the days _______we spent together.

I’m completely _______ at the way _______ his wife has treated him.