I'm going to swim______ the sea. （）

A．on

B．in

C．under

D．of

读一读，选择正确的单词填空。
【小题1】Welcome ___________(to/in) our school.
【小题2】Our library is __________(on/in) the first floor.
【小题3】This is the __________(teachers/teachers' ) office.
【小题4】—How many _________(student/students) are there in your class? —Forty-two.
【小题5】—_________(Is/Are) that the computer room? —No, it isn't.
【小题6】—_________(Are/Do) you have a computer room?  —Yes, we do.

Because we are back ______ school. （   ）

A．for

B．on

C．at

You can turn left Green Street. (  )

A．on

B．at

C．in

你帮助朋友在书桌下找到了他的尺子，你应该说：(   )

A．It’s on the desk.

B．It’s under the desk.

C．It’s in the desk.