---Is this key ________?--No, it isn’t. It’s ___________.

Studying in a foreign country is a different _________ and you can learn a lot.

—I have decided to take the entrance examinations to Qinghua University．—Wish you ____．

There’re many _______ on the big tree.

------Do you know the woman who is looking____ over a patient? ------ Yes. She is one of the best ____ in our hospital.