单项选择题 在有线电视系统前端设备安装中，固定的立柜、立架背面与侧面离墙面净距不应小于（）。

单项选择题 听力原文：W: What's the matter? I've mid you to arrive at 6:30, but now it's seven. Why don't you answer my phone?M: I'm sorry. I left my mobile phone in the office, so I cannot inform. you of my late arrival. Actually, I started one hour ago, but the traffic jam delayed me for 35 minutes.Q: When did the man start to meet the woman?(17)A．5:55.B．6:25.C．6:00.D．5:30.

单项选择题 听力原文：W: I'm worried about you. You look so pale. Do you have a headache? You need to take some medicine.M: A good rest will be more helpful. I was really exhausted at the wedding party last night. I'm sorry that we have to stay in the hotel, because this is the fast day of the honeymoon.Q: What's the relationship between the man and the woman?(18)A．Doctor and patient.B．Friends.C．Husband and wife.D．Boyfriend and girlfriend.