问题 选择题
如图所示为一磁流体发电机示意图,A、B是平行正对的金属板,等离子体(电离的气体,由自由电子和阳离子构成,整体呈电中性)从左侧进入,在t时间内有n个自由电子落在B板上,则关于R中的电流大小及方向判断正确的是(  )

A.I= ,从上向下

B.I= ,从上向下

C.I= ,从下向上

D.I= ,从下向上

答案

答案:A

阅读理解

阅读理解。

     Christopher Thomas, 27, was a writer by night and a teacher by day when he noticed he was always

tired and was losing weight fast. Diagnosed with diabetes (糖尿病), Thomas would need to inject himself

with insulin (胰岛素) three times a day for the rest of his life or risk nerve damage, blindness, and even death.

And if that weren't bad enough, he had no health insurance.

     After a month of feeling upset, Thomas decided he'd better find a way to fight back. He left Canton,

Michigan for New York, got a job waiting tables, nicknamed himself the Diabetic Rockstar, and created

diabeticrockstar.com, a free online community for diabetics and their loved ones-a place where over 1,100

people share personal stories, information, and resources.

     Jason Swencki's son, Kody, was diagnosed with type diabetes at six. Father and son visit the online

children's forums (论坛) together most evenings. "Kody gets so excited, writing to kids from all over," says

Swencki, one of the site's volunteers. "They know what he's going through, so he doesn't feel alone."

     Kody is anything but alone: Diabetes is now the seventh leading cause of death in the United States, with

24 million diagnosed cases. And more people are being diagnosed at younger ages.

     These days, Thomas's main focus is his charity (慈善机构), Fight It, which provides medicines and

supplies to people-225 to date-who can't afford a diabetic's huge expenses. Fight-it.org has raised about

$23,000-in products and in cash. In May, Thomas will hold the first annual Diabetic Rockstar Festival in the

Caribbean.

     Even with a staff of 22 volunteers, Thomas often devotes up to 50 hours a week to his cause, while still

doing his full-time job waiting tables. "Of the diabetes charities out there, most are putting money into finding

a cure," says Bentley Gubar, one of Rockstar's original members. "But Christopher is the only person I know

saying people need help now."

1. Which of the following is true of Christopher Thomas? [ ]

A. He needs to go to the doctor every day.

B. He studies the leading cause of diabetes.

C. He has a positive attitude to this disease.

D. He encourages diabetics by writing articles.

2. Diabeitcrockstar.com was created for _____. [ ]

A. diabetics to communicate

B. volunteers to find jobs

C. children to amuse themselves

D. rock stars to share resources.

3. According to the text, Kody _____. [ ]

A. feel lonely because of his illness

B. benefits from diabeticrockstar.com

C. helps create the online kid's forums

D. writes children's stories online

4. What can we learn about Fight It?  [ ]

A. It helps the diabetics in financial difficulties.

B. It organizes parties for volunteer once a year.

C. It offers less expensive medicine to diabetics.

D. It owns a well-known medical website.

5. The last paragraph suggests that Thomas _____. [ ]

A. works full-time in a diabetes charity

B. employs 22 people for his website

C. helps diabetics in his own way

D. ties to find a cure for diabetes

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