问题 问答题 简答题

评定汽油安定性的方法有哪些?

答案

参考答案:

(1)实际胶质,是评定汽油在使用过程中,在发动机进气管路及进气阀件上生成胶状沉积物倾向的指标。

(2)诱导期,是在加速氧化条件下评定汽油的氧化安定性指标之一,它表示车用汽油在储存时生成胶质的倾向。

(3)碘值与溴价(或溴指数),它们均是评定油品安定性的指标之一,油品中不饱和烃越多,碘值(或溴价、溴指数)则越高,油品的安定性也越差。

阅读理解

Since we are social beings,the quality of our lives depends in large measure on our interpersonal relationships.One strength of the human conditions is our possibility to give and receive support from one another under stressful (有压力的) conditions.Social support consists of the exchange of resources among people based on their interpersonal ties.Those of us with strong support systems appear better able to deal with major life changes and daily problems.People with strong social ties live longer and have better health than those without such ties.Studies over types of illnesses,from depression to heart disease,show that the presence of social support helps people defend themselves against illness,and the absence of such support makes poor health more likely.

Social support cushions stress in a number of ways.First,friends,relatives and co­workers may let us know that they value us.Our self­respect is strengthened when we feel accepted by others in spite of our faults and difficulties.Second,other people often provide us with informational support.They help us to define and understand our problems and find solutions to them.Third,we typically find social companionship supportive.Taking part in free­time activities with others helps us to meet our social needs while at the same time distracting (转移注意力) us from our worries and troubles.Finally,other people may give us instrumental support—money aid,material resources,and needed services—that reduces stress by helping us resolve and deal with our problems.

小题1:Interpersonal relationships are important because they can________.

A.deal with life changes

B.smooth away daily problems

C.make people live more easily

D.cure types of illnesses小题2:The researches show that people’s physical and mental health________.

A.has much to do with the amount of support they get from others

B.lies in the social medical care systems which support them

C.depends on their ability to deal with daily worries and troubles

D.is related to their courage for dealing with major life changes.小题3:Which of the following is closest in meaning to the underlined word “cushions”?

A.takes place of    

B.makes up of

C.lessens the effect of 

D.gets rid of小题4:Helping a sick neighbor with some repair work in spare time is an example of________.

A.instrumental support

B.informational support

C.social companionship

D.the strengthening of self­respect小题5:What is the subject discussed in the text?

A.Effects of stressful conditions.

B.Kinds of social support.

C.Ways to deal with stress.

D.Interpersonal relationships.

判断题