设函数f(x)在区间[0，+∞)上可导，且0≤f(x)≤． 证明：存在ξ＞0，使．
题型：问答题
问题：
设函数f(x)在区间[0，+∞)上可导，且0≤f(x)≤
．
证明：存在ξ＞0，使
．
题型：问答题
阅读理解
I am a good mother of three children.I have tried never to let my passion stand in the way of being a
good parent.
I no longer consider myself the center of the universe.I show up.I listen.I try to laugh.I am a good
friend to my husband.I have tried to make marriage vows (誓言) mean what they say.I am a good friend
to my friends, and they to me.With
out them, there would be nothing to say to you today.
So here's what I want to tell you today:Get a life.A real life, not a desire of the next promotion (提升),
the bigger paycheck, the larger house.
Get a life in which you are not alone.Find people you love, and who love you.And remember that love
is not leisure (休闲), it is work.Pick up the phone.Send an email.Write a letter.And realize that life is the
best thing and that you have no business taking it for granted.
It is so easy to waste our lives, our days, our hours, and our minutes.It_is_so_easy_to_exist_instead_
of_to_live.I learnt to live many years ago.Something really, really bad happened to me, something that
changed my life in ways that, if I had my choice, it would never have been changed at all.And what I
learned from it is what, today, seems to be the hardest lesson of all.
I learned to love the journey, not the destination.I learned to look at all the good in the world and try
to give some of it back because I believed in it, completely and totally.And I tried to do that, in part, by
telling others what I had learned.
By telling them this:Read in the backyard with the sun on your face.Learn to be happy.And think of life as a deadly illness, because if you do, you will live it with joy and passion (激情) as it ought to be lived.
1. It can be inferred from the passage that________.
A. the author is a success in personal life
B. the author didn't try her best to work well
C. the author spent all her time caring for her children
D. the author likes traveling very much
2. How did the author form her view of life?
A. Through social experience.
B. By learning from her friends.
C. Through an unfortunate experience.
D. From her children and husband.
3. By the underlined sentence "It is so easy to exist instead of to live" in the fifth paragraph,
the author really means that people tend to________.
A. make a living rather than live a real life
B. work rather than enjoy life
C. waste a lot in life
D. forget the most important lessons in life
4. What's the author's 
attitude toward work?
A. Do it well to serve others.
B. Earn enough money to make life better.
C. Try your best to get a higher position and a pay raise.
D. Don't let it affect your real life.