Those relatives(亲戚) were _______. After a few days, he got _______ and missed his parents very much.

The group’s research has done much toourknowledge of the HIV virus．

He kept thinking of the question whether it was ____ for his father to change the habit of a life time in such a short time

Nancy, are you sure you can do it by yourself — .I did it before.

– He is thirty-two.