He has two daughters , and _________of them are workers

Could you me with information about Student Exchange Program?—Yes, of course. It’s on this piece of paper.

Bill Gates has created a wonderful “window” ______ people can surf the Internet freely．

Do you have________ books on Chinese food?—Yes, I have______.

Yesterday ___ 8-year-old boy fell into the river.____ boy was saved by ______policeman.