问题 多选题

关于摩擦力,下列说法正确的是(  )

A.摩擦力的方向总是和物体运动方向或运动趋势方向相反

B.相互接间的正压力增大,摩擦力一定增大

C.静止的物体受到的静摩擦力的大小和接触面材料的粗糙程度无关

D.运动的物体可能受到静摩擦力

答案

A、摩擦力的方向不一定和物体的运动方向相反,也可能与运动方向相同,故A错误;

B、物体受静摩擦力时,相互接间的正压力增大,摩擦力不变,故B错误;

C、静止的物体受到的静摩擦力的大小是根据平衡条件去求解的,跟接触面材料的粗糙程度无关,故C正确;

D、运动的物体也可以受到摩擦力作用,如斜向上运动的传送带上的物体受到静摩擦力作用,故D正确;

故选 CD

阅读理解

Some students like to translate(翻译) when they practice speaking English. Translation is a very difficult exercise. During a conversation, we don’t really have time to translate what we understand. When we use translation, we don’t develop the necessary reflexes (反应能力) needed to speak and understand a foreign language. It is important to build up reflexes right from the beginning. It will help you later when your skills are good enough to take a conversation.

Here is some advice on how to build up reflexes when you only have basic words and grammar.

Relax!

No one is checking you except yourself! Look at each communication experience as an adventure. Try to relax first when you speak English. You will pick up on small details.

Context(上下文) is your friend.

What is context? It means the situation in which something happens and that helps to understand it. (2)We can make good guesses about what is being said by using the context. It will be easy when you think about the context. You will feel much more comfortable and confident if you remember that.

Ask questions what you want to know.

After you have proudly asked for tickets at the train station, the booking-office clerk (售票员) spoke a long sentence to you about the place and the time. You may be a little unclear or have only understood a part of it. However, you can ask questions about what you want to know, such as, “Did you say…?” and “Would you repeat that more slowly?”. So that you can easily move the communication forward. Use body language.

Use body language to go with your words when you __(1)___ to learn a __(1)_____ language. The person you are speaking to only wants to understand you and will be carefully listening to you. As you become more proficient (熟练的) in your second language, you will depend(依靠) more on the language and less on body language. But there is no shame for a beginner.

小题1: 在(1)处的空白处分别填入一个适当的词使句意完整、上下文通顺。

________  __________

小题2: 将(2)句译成中文。

_______________________________________________________________________________

小题3:回答问题: What does the writer want us to do first when we speak English?

_______________________________________________________________________________

小题4: 在文中找出与 Maybe you didn’t hear clearly or understand all of it.意思相同或相近的句子,

并将它写在答题卡上。

_______________________________________________________________________________

小题5: 在文中找出最能表达该短文主题的句子,并将它写在答题纸上。

_______________________________________________________________________________

单项选择题