There are many volunteers ______ are helping the children in Sichuan.— And most of them are college students.

I have two story-books. One is for you and ______ is for your sister.

Does the wolf live ________ the forest or ________ the desert? [ ]

People in the west make_____a rule to buy Christmas presents for their relatives and friends.

Where is Jack? —I noticed that he ________the teacher’s office just now.