问题 问答题 简答题

试分析当进气压力传感器或其电路出现故障时,失效保护系统是如何工作的?

答案

参考答案:

在D型电控燃油喷射系统中,如果进气压力传感器或其电路发生故障,ECU无法按进气量计算喷油时间,将引起发动机失速或不能起动。此时,失效保护系统将使ECU按设定的固定值控制喷油量,或启动应急备用系统维持发动机运转。

阅读理解

阅读理解。

     Have you ever thought of taking a train and having an adventure (奇遇)?Riding the train can

be a real adventure.That is how I feel every time I take Amtrak.I often take a fourhour trip to

visit my children.Every time I take this trip I never know what  will happen.

     Last week when I was on the train and over an hour into the train ride,there was a man sitting

by himself in the back of the train carrying on a mobile phone conversation- in another language.It

was loud and disturbed most of the people on the train.I think it was annoying.

     Fortunately I sat next to a wonderful old lady who was taking a twoday trip by train.She said

her two daughters were distraught at the thought of her driving for three days to reach her home,

although she had no trouble driving.The train ride was the only choice for her.She loved to look

out of the window and watch the world go by on the train.

     She was fun to talk to and asked me when my children started being parents.That is a very

good question.Both of us are old and have children.She asked that same question from time to

time.

     There are always many people on the train from all  walks  of life,different  countries,and 

 many languages.Riding the train is a great way to increase your knowledge and take in all kinds

of cultures.If you get hungry,you can buy food in the food car at any time.If you need to use the

restroom there is always one available.

     It sure beats driving the car,which has to stop for food and restrooms.And it is better than

taking the bus.

1.According to the passage,the purpose of the author's train ride was________.

A.to do business        

B.to see her children

C.to visit places of interest  

D.to see her old friends

2.Which of the following is the closest in meaning to the underlined word "distraught" in Paragraph 3?

A.Disappointed.  

B.Satisfied.

C.Worried.  

D.Pleased.

3.Which of the following is TRUE about the old lady sitting next to the author?

A.She is too old to drive now.

B.She does not like to take trains.

C.Although she is old,she has a good memory.

D.Her daughters live far away from her home.

4.In the author's opinion,on the train Amtrak________.

A.the services are quite good

B.the food is terribly expensive

C.all the passengers are polite

D.all the passengers are American

5.What is the best title for this passage?

A.Train ride-a cultural experience

B.A painful experience on the train

C.The history of Amtrak

D.A wonderful lady

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