问题 填空题
某工厂生产某种产品的固定成本为200万元,并且生产量每增加一单位产品,成本增加1万元,又知总收入R是单位产量Q的函数:R(Q)=4Q-
1
200
Q2,则总利润L(Q)的最大值是______万元,这时产品的生产数量为______.(总利润=总收入-成本)
答案

有题意总利润为

L(Q)=4Q-

1
200
Q2-(200+Q)=-
1
200
(Q-300)2+250.

当Q=300时,总利润的最大值是250.

故应填 250,300.

解答题
阅读理解

阅读理解。

      Listen carefully, working people, we would like to tell you something that could save your precious time

and money! Best of all, it is free!

      It's "no".

      What do you ask? We'll say it again:"No".

      Sweet and simple "no".

      Say "no" at your office and see how quickly that pile of work on your desk disappears.

      "Saying 'no' to others means you are saying 'yes' to yourself," said Leslie Charles, a professional speaker

from East Lansing, Michigan.

      "Time is precious. People are spending money buying time. And yet we are willing to give up our time

because we can't say 'no'."

      Susie Watson, a famous writer, said people who always say "yes" need to say "no" without guilt (内疚)

or fear of punishment. "I would rather have someone give me a loving 'no'than an obligated (强制的) 'yes',"

she said.

      Susie Watson says she feels "no" obligation to give an explanation when she says "no" either socially or

professionally. Does she feel guilty about it? "Not at all," said Watson, who is director of advertising and public

relations at Timex Corp in Middlebury, Connecticut. "Most people are afraid of saying 'no'… My advice is to

say 'yes' only if you don't mean 'no'."

      Watson said "no" is the most effective weapon against wasting time. "Every year there are more demands

on your time… Other people are happy to use up your time," Watson said. Time saving appears to be "no'"

greatest friend.

      "No" can be your new friend, a powerful tool to take back your life. "No" may even take you further in

the business world than"yes".

      "No" is power and strength. "No" now seems completely correct."Saying 'no' isn't easy. But finally it's

greatly liberating," Charles said. But, he added, a "no" project needs to be worked on every day because it is

hard to change long-term habit. 

      But, he also warns:"Don't go to extremes. Don't find yourself saying 'no'to everything. In return you

should learn to hear 'no'."

1. The sentence "you are saying 'yes' to yourself" means _____.

A. you can have more time to play with others

B. you needn't care about other's feeling if you are happy

C. you are selfish and treat others rudely

D. you can deal with your business as you have planned

2. When you say "no" to others, you should say it in a _____.

A. secret way   

B. polite way

C. proud way     

D. guilty way

3. In Watson's opinion, people can save much time on condition that _______.

A. they say "no" at a suitable time

B. they say "no" as much as possible

C. they are afraid of saying "no"

D. they make others angry at them

4. If a person says "no" to everything, the result he or she receives may be that he or she _____.

A. enjoys a wonderful life

B. makes a lot of money

C. faces difficulty in life  

D. forgets to say "yes" in the end