问题 选择题

新鲜水果常用保鲜袋包起来,目的是

A.防止虫蛀

B.降低蒸腾作用

C.降低呼吸作用

D.保持水果细胞生活的适宜温度

答案

答案:C

此题考查的知识点是蔬菜的呼吸作用需要氧气,解答时可以从氧气与呼吸的关系方面来切入.

解:氧气:氧气是植物正常呼吸的重要因子,氧气不足直接影响呼吸速度,氧气少呼吸作用弱,氧气多,呼吸作用强.蔬菜进行呼吸作用需要消耗氧气,分解有机物,影响蔬菜的储存时间.根据氧对呼吸作用影响的原理,在贮存蔬菜、水果时就降低氧的浓度,减少有机物的消耗,延长蔬菜的储存时间,保鲜膜包装的蔬菜,保鲜膜内的氧气较少,抑制了蔬菜的呼吸作用,消耗的有机物较少,因此可以延长蔬菜储存的时间.

故选:C.

解答此类题目的关键是理解植物的呼吸作用需要氧气.

阅读理解

Cameron thought of himself as merely organized.He certainly did not consider that he took great pains over anything ,he did just enough to get it right.Exactly right, of course as he was fond of telling his staff, “if it’s not exactly right, it’s wrong”.Occasionally a worker might be sad on hearing these words, because it meant another hour or so of going over the same bit of work, correcting the mistakes which Cameron had patiently pointed out.And doing the corrections exactly right of course.

Strangely enough ,his department had the reputation for performing the highest quality work in the company ,and it was seen, and not only by those who worked in the department ,as a sort of elite(出类拔萃)unit.Those programs that had to work first time, straight out of the box, Cameron’s men got those.“It’s mission(任务)critical—give it to Cameron” was almost a catch—phrase with his team.

It helped that Cameron was not merely particular about things.He wanted things done just so ,not because of a personal taste ,but because he had discovered through patient experimentation that this was the best way for it to be done.

小题1:Cameron was a            

A.software programmer

B.a chief scientist

C.quality controller

D.head of department小题2:“Mission-critical” work given to Cameron because       

A.Cameron’s work was error—free

B.Cameron was critical

C.he didn’t mind working late

D.he had a good team小题3:Working for Cameron, people felt that          

A.they were part of an elite

B.their mission was critical

C.Cameron was very particular about things

D.Cameron was patient and responsible小题4:According to the underlined part in paragraph 5,what is meant by someone “who couldn’t cut it”?

A.He didn’t cut corners.

B.He wasn’t good enough.

C.He had the wrong measurements.

D.He was a perfection.小题5:What can we learn about Cameron?

A.He never got things Wrong.

B.He didn’t allow for any mistake.

C.He encouraged work to be done in office hours.

D.He was often misunderstood.小题6:The attitude of the author towards Cameron is that of being       

A.positive

B.sympathetic

C.non-subjective

D.optimistic

名词解释