问题 选择题
电气化铁路的输电线常用图所示的方式悬挂在钢缆上.钢缆的A端固定在电杆上,B端连接在滑轮组上.滑轮组由a、b、c三个滑轮构成,配重P由多个混凝土圆盘悬挂在一起组成,配重的总重为G,若不计摩擦和滑轮的重量,则以下说法中正确的是(  )

A.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

B.a为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

C.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为3G

D.a、c为动滑轮,B端钢缆受到滑轮组的拉力大小约为G

答案

答案:A

阅读理解

MY Chinese friend is going to the US and he is nervous about what to talk about. “Talk about the weather,” is my advice.

“How are you?” is often followed by comments about the weather. “Nice day today.” “Cold/hot enough for you?” “Will it ever stop raining?” “Some winter we’re having.” “Can’t remember a winter/summer so cold/hot.” “Whew, it’s hot out there.”

These introductory statements are often followed by a long conversation entirely about weather conditions. Past, present and – with global warming – speculation (推测) about the future.

Our fascination with weather might seem silly, but the real purpose behind those endless discussions is small talk. Weather’s a safe topic of conversation. As a group, we Americans seem to enjoy chatting with those around us. Whenever we stand in line at the grocery store, we tend to engage in this sort of conversation with other people standing in line with us. If I were seated next to another American on any form of public transport, I’d expect both of us to make some harmless comment about the weather as a way of acknowledging (承认) each other’s presence (存在). At parties, the weather is a common topic, especially with those you are meeting for the first time.

In contrast we are taught to avoid certain topics like religion and politics. Weather is neutral (中性的); you don’t have to have an opinion about it, just make a statement of a fact. What is truly interesting is the fact that we can go on and on about it.

My Chinese friend has a hard time understanding why we put so much effort into this topic – and why I warn him about bringing up much more “interesting” subjects like salaries or how much something costs.

Sometimes it is tricky (复杂的) to wend (行走) one’s way through winding cultural roads, especially those that are never taught in books.

小题1:What does the writer suggest her Chinese friend should talk about with people in the US? (No more than two words)

小题2:Why do Americans enjoy talking to people around them about the weather, in writer’s opinion? (No more than ten words)

小题3:List four topics that people should avoid talking about in the US. ( No more than 5 words)

单项选择题