问题 填空题

如图,在倾角θ为37°的固定光滑斜面上放的一块质量不计的薄板,水平放置的棒OA,A端搁在薄板上,O端装有水平转轴,棒和板间的滑动摩擦系数为4/15,薄板沿斜面向上或向下匀速拉动时,则棒对板的压力大小之比为   ,所需拉力大小之比为     

答案

本题考查有固定转动轴物体的平衡条件。设棒的质量为m,长为l,向上拉动时,受力如图甲,

向下拉动时,受力如图乙,

解得压力之比为N1:N2=2:3,

所以拉力之比为

完形填空

Everyone has good habits and bad habits.

Unfortunately,while identifying(识别) our bad habits is easy,changing them is not.Here are some tips to help you develop good habits to achieve your goals.

1. Identify Your Bad Habits

You should be able to understand your own  

behavior and how they can either help or

hinder(阻碍)your success.To help you out,

think about how others act and about how   

you react.Then identify those actions that

anger,upset,or annoy you. 

2. Write Them Down

Once you have identified the behavior you    

wish to improve,write them down on a piece

of paper.Choose one,two at most,and focus

only on those.Make notes about them,and

post those notes in prominent(显眼的) places

to serve as a constant reminder to you to

correct your behavior in those areas.

3. Live for Today

Try not to think of what you have to do

tomorrow,next week,or next  month.

Instead,focus on what you are doing right  

now.Give each person you deal with your

undivided attention,and try not to let other

aspects of your life interfere(打扰).

4. Seek Help

Let your family and friends know about the 

changes you wish to make in your life.Ask

Them _____ .Sometimes learning to accept advice is a new habit in and of itself.By receiving advice from people you trust,you will be able to learn whether or not you will be successful in building new habits. Change is 

not easy.It takes effort,hard work,and determination. As you begin to build new habits, you will need to think about them constantly to prevent the old habits from taking over. With time and practice,you will have developed new behavior that can lead you to success.

1. What is the best title of the passage?(Please  answer within 10 words.)

2. Which sentence in the passage is the closest in meaning to the following one?

You should concentrate on those bad habits you have that you most want to get rid of.

3. Please fill in the blank in the fifth paragraph with the proper words.  (Please answer within

6 words.)

4. What’s your own opinion on getting rid of bad habits?  (Please answer within 20 words.)

5. Translate the underlined sentence in the last paragraph into Chinese.

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