设曲线y=xlnx-e上点(e,0)处的切线与直线ax+y+1=0垂直,则a=_

题型:填空题

问题:

设曲线y=xlnx-e上点(e,0)处的切线与直线ax+y+1=0垂直,则a=______.

考点:函数的极值与导数的关系直线的方程
题型:填空题

价值工程是以提高产品()为目的。

A.功能

B.寿命

C.效益

D.价值

题型:填空题

阅读理解。

     It was a warm April day when a big fat envelope came in the mail from the only college I had ever imagined

attending. I tore open the packet. My eyes were fixed on the word "congratulations". I don't remember ever

smiling so wide.

     Then I looked at my financial (财政的) package.

     The cost of Dream School's tuition (学费), room and board was around $ 40,000-an impossible sum! How

could I afford to attend? What good reasons did I have to go there when three other fine colleges were offering

me free tuition? My other choices were good, solid schools even if they weren't as famous as my first choice.

     In my mind, attending my dream university would be the only way to realize my dream of becoming a world-

class writer. My parents understood how I felt. They told me that even though it would be a financial problem,

I could go wherever I would be happiest. But as I was always careful with money, I wasn't sure what to do.

     One of the schools that offered me a full ride had an informational dinner one night in the spring. Considering

my parents' financial difficulties, I decided to drive the 45 minutes and attend. At first, all I had planned to do

was smile politely, eat free food, listen quietly. But I surprised myself.

     At dinner the president of the university talked about the wonderful activities on campus (校园) including

guest lectures and social gatherings. He also made it perfectly clear that free food would be offered at all future

events. He continued with explanations of professors, class sizes, activities, and sporting events on campus. As

he spoke, I began to realize that this school, though not as good as my first choice, might be the best one for

me. It seemed small yet with many great programs. It seemed challenging yet caring.

     As the president ended his speech, we clapped politely and pushed back our chairs. As I walked out that

door, a feeling of comfort washed over me. Looking at the campus that night, I realized that I would be spending

the next four years right there.

     In all honesty, my university is not as well-known as my "dream" university. However, it turned out to be

the right choice of schools for me.

1. How did the author feel when he started to read the letter?[ ]

A. He was uncertain which school to go to.

B. He was lost in his dream.

C. He was worried about the money.

D. He was full of joy.

2. We can learn from the passage that the parents were _____. [ ]

A. honest

B. supportive

C. strict

D. decisive

3. In Paragraph 5, "offered me a full ride" can be replaced by "_____". [ ]

A. would pay for transport to the school

B. would show me around the campus

C. would offer free meals at all events

D. would charge me nothing for tuition

4. What does the author mainly want to say? [ ]

A. You should consider comfort in your choice of schools.

B. Your second-choice college may actually by your best fit.

C. You should try your best to attend your dream school.

D. Your choice of schools should be based on their fame.

题型:填空题

只有通过操作系统才能完成对计算机的各种操作。 ( )

题型:填空题

在组合式曲轴套合方法中,不允许使用的是()联接工艺。

A、冷套法

B、红套法

C、键联接法

D、焊接法

题型:填空题

下列关于财务比率的表述,正确的是()。

A.盈利能力比率体现管理层控制费用并获得投资收益的能力 

B.杠杆比率用来判断企业归还短期债务的能力 

C.流动性比率用于体现管理层管理和控制资产的能力 

D.效率比率用来衡量企业所有者利用自有资金获得融资的能力

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