馈线安装在走线架中时，垂直方向至少每隔（）米用馈线卡固定一次。
A、0.5
B、1
C、1.5
D、2
参考答案：B
根据各组对话内容，从下面提供的5个选项中选出能填入空白处的最佳选项。
A:Excuse me. Could you give me a hand
B:()
A:I want to move this desk out of the office.
A．Sure. What is it
B．It’s very nice of you to say so.
C．It’s nothing.
D．Have a nice trip!
E．Certainly, Here you are.
自有人类以来，警察就普遍存在于各个历史时期。 ( )
