电能表接在家庭电路中，是为了测量 A．电功率 B．电功 C．电流 D．电压

某商店欲购进甲、乙两种商品，已知甲的进价是乙的进价的一半，进3件甲商品和1件乙商品恰好用200元．甲、乙两种商品的售价每件分别为80元、130元，该商店决定用不少于6710元且不超过6810元购进这两种商品共100件．

（1）求这两种商品的进价．

（2）该商店有几种进货方案？哪种进货方案可获得最大利润，最大利润是多少？

I don't want to continue working with him, for I  can't bear his    _complaints recently.[ ]

A. continuous                

B. constant

C. continuously              

D. constantly

下列各组物质中属于同位素的是

A． O₂和O₃

B．正丁烷和异丁烷

C．¹²C和¹⁴C

D．Na₂O和Na₂O₂

阅读理解。

      Being the head of a high school for many years, I grew tired of budget meetings, fundingcuts,

and many other administrative chores and started to dream of retirement. Sitting in trafficon a

weekday morning, I would find my mind wandering. I would imagine spending time withmy

grandchildren, quiet evenings with my wife, traveling, or rediscovering some great books. Itold

myself that I wouldn't sign myself up for any committees, any classes, or anythingrequiring a

schedule.

     My first day of retirement came at last! I cooked a great breakfast for my wife and me,leisurely

read the paper, cleaned a bit of the house, and wrote a few letters to friends. On thesecond day,

I cooked breakfast, read the paper …On the third day, This is retirement? Itried to tell myself

that it was just the transition, that those golden moments were right roundthe corner, and that I

would enjoy them soon enough. But something was missing.

     A former colleague asked a favor. A group of students was going to Jamaica to work with 

children in the poorest neighbourhood. Would I interrupt my newfound "happiness" and returnto

the students, just this once? One trip. That's all. My bags were packed and by the door.

     The trip was very inspiring. I was moved not only by the poverty I saw but also by thesense

of responsibility of the young people on the trip. When I returned home, I offered to workone day

a week with a local youth organization. The experience was so positive that I was soon volunteering

nearly full-time, working with students across North America to assist them in their voluntary work.

     Now,it seems, the tables have turned . Some days I am the teacher, other days I am the student.

These young people have reawakened my commitment to social justice issues by challenging me to

learn more about the situation in the world today, where people are still poorand suffer because of

greed, corruption and war. Most importantly, they have given me the opportunity to continue to

participate in helping to find solutions. In return, I help them do their charitable projects overseas. 

I've gone from running one school to helping oversee the construction of schools in twenty-one

countries!

1. What did the writer expect to do after he retired?

A. To stay away from busy schedules.

B. To write some great books.

C. To do some voluntary work.

D. To plan for his future.

2. Why did the writer decide to go to Jamaica?

A. He missed his students in that country.

B. He couldn't reflise his colleague's favor.

C. He was concerned about the people there.

D. He was not satisfied with his retired life.

3. The underlined part "the tables have turned" (Paragraph 5 ) means that thewriter.

A. improved the situation in his school

B. felt happy to work with students again

C. became a learner rather than a teacher

D. changed his attitude toward his retired life

4. What does the writer think of his retired life now?

A. Disappointing.

B. Troublesome.

C. Promising.

D. Meaningful.