I don’t like physics ______ it’s too difficult for me.

We’re heard much _______ about the missing plane, but we still don’t know where it is.

. —He must be a true friend, isn’t he? —Of course he is. He seldom ____________ a bad word about others.

 ---What’s wrong with you?---I have a _______. Because I ate too much yesterday.

---Who’s the most modest boy in your class?---Daniel. He never __________ in public.