问题 选择题

小明两次用力举高物体,第一次迅速举起,第二次缓慢举起到相同的高度,则(  )

A.第一次做功少,两次做功的功率相同

B.第一次做功多,两次做功的功率相同

C.两次做功相等,但第一次做功的功率大

D.两次做功相等,但第二次做功的功率大

答案

(1)两次过程中:物体重力不变,高度不变,根据公式W=Gh可知,两次所做功大小相等;

(2)根据公式P=

W
t
可以看出,两次做的功一样多,第一次的时间小于第二次的时间,所以第一次的功率大于第二次的功率.

故选C.

阅读理解

阅读表达。

     For years Tom Anderson's life was withered(枯萎) up by the memory of his part in an outdoor

adventure that resulted in the death of one of his classmates.He and his wife separated after six years

of marriage.Then the news about Tom changed.His wife Betty came back;he earned a fine position

in a company.

     One day he told me what had changed his life:I used to think, 'Nothing can undo what I have done'.

The thought of my guilt would stop me in the middle of a smile or a handshake.It put a wall between my

wife and me.Then I had an unexpected visit from the person I feared most to see-the mother of the

college classmate who died."Years ago", she said, "I found it in my heart, through prayer, to________.

Betty forgave you.So did your friends and employers." She paused, and then said strictly, "You are the

one person who hasn't forgiven Tom Anderson.Who do you think you are to stand out against the people of this town and the Lord Almighty?""I looked into her eyes and found there a kind of permission to be

the person I might have been if her boy had lived.For the first time in my adult life I felt worthy to love

and be loved."

     It is only through forgiveness of our mistakes that we gain the freedom to learn from experience.But

_forgiving_our_shortcomings_doesn't_mean_ignoring_that_they_exist.On_the_contrary, it_means_facing_

them_honestly, realistically.Unless you forgive, you cannot love.And without love, life has no meaning.

Forgiveness is a good quality.

1. What is the best title of this passage?(within 10 words)

________________________________________________________________________

2. Fill in the blank with proper words to complete the sentence in paragraph 2?(within 5 words)

________________________________________________________________________

3. Which sentence in the passage can be replaced by the following one?

I would hold back my smile and stop shaking hands with people at the thought of my fault in the adventure.

________________________________________________________________________

4. What would you do when someone does something wrong to you indeliberately?Why?(within 30 words)

________________________________________________________________________

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

________________________________________________________________________

单项选择题