若方程组x-2y=414x+my=1有无数个解，则m等于（ ） A．12 B．-12

阅读理解。

     An American housewife was pushing her shopping basket through a supermarket with one hand.

With the other hand she was holding on to her small child.She arrived at the checkout counter, saying

to herself, "Now another 20 minutes." But her bill was ready in 20 seconds.

    Twenty seconds? Yes,a new machine is doing the job.It reads a stamp of black and white lines on

each can, box or bottle. These little lines give the computer all the information it needs: the kind of

products,the price and the tax. The girl at the counter simply moves the goods along the front of the "eye"

of the machine. And the bill is ready In no time.

    The machines now used in 20 supermarkets in the United States save a lot of time and money, And

they don't make as many mistakes as people do. Some shoppers,however,are complaining that they

cannot read the prices of the goods. All they can see are little black and white lines. The prices are on

theshelves but they want them on the goods.Many people are not sure whether the expensive new

machines are honest shopkcepers!

1. What did the housewife mean by saying"Now another 20 minutes"'?

A. She had waited 20 minutes in front of the counter.

B. She would spend 20 more minutes selecting goods.

C. The bill could be ready in more than 20 minutes.

D. Shc had to wait anottaer 20 minutes.

2. What does the word "stamp" mean in this story?

A. 邮票            

B. 标记    

C.商标    

D. 信誉卡

3.Choose the correct order in which the new maehine does its work.

A. The computer gets the information it needs from the lines.

B. The salesgirl moves the goods in front of the new machine.

C. The bill is ready.

D. The new machine reads the black and white  lines on eachcan, box or bottle.

A. a,b,c,d            

B. b,c,a,d

C. d,b,a,c            

D. b,d,a,c

4. The passagc might be written ______.

A. years ago        

B. recently

C. last year        

D. months ago

5. Which of the following is NOT true according to this passage?

A. The new machine makes fewer mistakes.

B. None of the customers like the new machine.

C. With the help of the new machine the shoppers don't have to wait so long for their bills.

D. Many people are afraid that they will possibly be cheated by the new machine.

下列没有语病的一项是（０９湘潭模拟）　　　　　（　　　　）

A．这次席卷全球的金融危机已经从深度和广度上都衍化成了一场世界各国实体经济有着显著影响的经济危机。需要回答的迫切问题就是这场危机下的实体经济会向哪一方向继续发展。

B．春节期间，全国各地娱乐场所、商场市场、高层建筑等场所连续发生火灾，不仅在社会上产生了较大的负面影响，而且给国家和人民生命财产造成了重大损失。

C．2月10日，美国一颗通信卫星与一颗俄罗斯已报废的卫星在太空中相撞。专家指出，美俄卫星相撞产生的碎片对哈勃太空望远镜和地球监测卫星的危害会更大。

D．在金融危机的影响下，国内就业形势十分严峻。公安机关提醒广大待就业高校毕业生在求职时对职业中介要增强防范意识，以免因求职心切而上当受骗。

铝及铝合金管道保温时，不得使用（）等带有碱性的材料，应选用中性的保温材料。

A．石棉板

B．石棉绳

C．毛毡

D．玻璃棉

治疗咳嗽痰稠，鼻咽干燥，属燥热伤肺者，宜选用（）

A.薄荷

B.升麻

C.葛根

D.细辛

E.桑叶

A321飞机洗手间门关上但未锁上时，日光灯管以（）的亮度开启。

A.100%

B.75%

C.50%

D.25%