--Did you go to Kenli during the Peach Blossom Festival (桃花节)?

--Yes. The flowers were beautiful. Bees were flying         them.

A．in

B．among

C．between

D．through

扫描监视的目的是收集（）状态的变化。

A.用户线回路

B.信号设备

C.I/O接口