向移动交换中心或基站供电的电力线,在进入建筑物时,宜采用地下电缆引入,电缆的户外端离建筑物的距离不宜小于()m。
A.30
B.40
C.50
D.60
参考答案:C
— Do you know whether they talked about their work or their family?
— As matter of fact, I couldn’t hear it clearly, as they talked in whisper. [ ]
A. the, a
B. the, the
C. a; a
D. a; the
要从165个人中抽取15人进行身体检查,现采用分层抽样的方法进行抽取,若这165人中老年人的人数为22人,则老年人中被抽到参加健康检查的人数是______.