在微蜂窝附近采用无源方式，用馈线直接引用基站信号；距离微蜂窝较远的地方采用干线放大器，将信号放大后使用。（）
参考答案：对
—Have you seen _____ empty box?
—Do you mean _____ box you showed to me yesterday? I put it in your
schoolbag.[ ]
A. a, the
B. an, a
C. an, the
D. the, a
—Are you free _____ Friday?
—I have nothing _____. [ ]
A. in, to do
B. on, to do
C. on, do
D. at, to do
