问题 选择题

某户人家共有10盏灯并联在电路上,为了使电路中的总电流最小,那么应该(  )

A.灯全部开亮

B.灯全部关掉

C.只开一只灯

D.开两只灯

答案

根据欧姆定律可知:在电源电压不变时,总电阻越大,电路中的电流越小;

根据电阻的并联可知,并联电路中电阻并得越多,总电阻越小;

所以要使电路中的总电流最小,减少并联电阻的个数即可;

综合选项可知当灯全部关掉时,电路中电流最小.

故选B.

阅读理解

Long queues at cinemas buying hot tickets for blockbusters(巨片) will become rare as Beijing residents will be able to order film tickets via cell phone networks in a month.

Film ticket circulation service on cell phone, also called the “Green channel of film tickets ordering”, is aiming at lowing the cost of ticket circulation and easing the ticket distribution pressure on such popular film-watching days as summer and winter vacations or Valentine’s Day.

“People log onto the net through cell phones, then choose cinema seats, watch trailers, browse information for new films and read cinema introductions,” said Guan Zheng, the publicity chief of Xingmei Digital Media Company Ltd., the service provider.

“Film fans can enjoy various discount prices if they order tickets via cell phones,” Guan said.

Meanwhile, the cell phone ticket circulation platform provides subscribers general mobile phone services like jokes, videos, flashes, phone ring downloads and games.

The service is about to be put into trial at the Beijing-based Xingmei International Cinema for a month before being putting into use at other cinema chains both in and outside Beijing, as the service is going to be improved through gradual expansion, said Guan.

China’s film industry that is being restored has seen more and more enthusiastic moviegoers. Up to the end of 2009, China has had more than 5,000 specialized cinemas, among which there are 2,243 modern cinemas with 3, 668 silver screens and 56 cinema chains.

Currently, many people buy film tickets on the Internet or by phoning the cinema’s ticket office or simply queuing at the cinema gate. More people want to buy tickets on popular days like May Day holiday, National Day holiday or Valentine’s Day. Yet the inefficient ticket circulation system contributes the most to the failure.

小题1:What can we learn from the passage?

A.The price of the ticket ordered via cell phone will be lower.

B.Ordering tickets through the net can get good seats.

C.Few people would like to watch films on the net.

D.More and more people like to watch films on the net.小题2:What does the underlined part “watch trailers” in the third paragraph mean?

A.You can watch films after downloading them.

B.You can watch commercial ads free of charge.

C.You can watch short ads for new movies.

D.You can watch films on the net at home.小题3:What does the passage imply?

A.The service is only intended to put into use at the cinema in Beijing for a month.

B.China’s film industry saw the decreasing number of moviegoers by the end of 2009.[

C.The traditional ticket selling system makes it hard to get film tickets on popular days.

D.The green channel of tickets ordering is aiming at provides general mobile phone services..小题4:The best title for the passage would probably be ________.

A.Rare Beijingers to watch films on the net

B.Few Beijingers to buy film tickets in line

C.Beijingers to watch films via cell phone

D.Beijingers to order film tickets via cell phone

单项选择题