This book is said to be a special one,which________many events that cannot be found in other history books.
Many teens don’t have enough sleep because they have too much homework, which ______ them up at night.
Food safety is ______ important, so the government spares no efforts to prevent food pollution.
—May I try the jacket on? —______,but I think it will be too small for you.
She thinks she can get there on time, _______she?
The headmaster thought _______ necessary to invite Professor Brown to give us a lecture.