题目

如图为节日里悬挂灯笼的一种方式，A、B点等高，O为结点，轻绳AO、BO长度相等，绳中拉力分别为FA、FB，灯笼受到的重力为G，下列表述正确的是（      ）A．FA的大小一定小于G         B．FA与FB大小相等C．FA与FB是一对平衡力        D．FA与FB大小之和等于G  答案：B解析:略 听下面一段对话,回答1至3小题.1.What is the main idea of the speech?A. Hotlines have become common in China.B. His viewpoint on hotlines.C. Hotlines are good ideas.2. Why does the host have to explain and answer?A. Because the host knows little about the topic.B. Because the host wants to express his hope.   C. Because of the caller's ignorance.3.  What does the speaker suggest?  A. The caller who doesn't know what is going on is not allowed to take part in.  B. The host should pay no attention to the caller's question.C. Let the host know it is a waste of time.