问题 问答题

三只轻纸球分别用丝线悬挂着,其中任意两只球靠近时都互相吸引,则下列结论正确的是(  )

A.三球都带电

B.有两个球带同种电荷,第三个球不带电

C.只有一个球带电

D.有两个球带异种电荷,第三个球不带电

答案

A、如果三个小球都带电,至少有两个是带同种电荷,当它们两个靠近,会互相排斥,与题意不符;

B、当两个带同种电荷的小球靠近时会互相排斥,与题意不符;

C、如果只有一个小球带电,那么其他两个不带电的小球靠近时,它们不会吸引,与题意不符;

D、如果两个小球带异种电荷,第三不带电,当带异种电荷的两个小球靠近时,互相吸引;而带电小球分别与不带电小球靠近时,也能吸引不带电的小球,D符合题意.

故选D.

阅读理解

For those who are tired of doing the laundry, Samsung has found an answer: a washing machine that can tell you when your laundry is done via a smartphone app (application).

Strange though it may seem — "my wife already does that" was a common response among attendees viewing the device when it was introduced at the Consumer Electronics Show (CES) this week — Samsung is just one of many appliance makers racing to install a large number of internet-connected features in machines in an effort to make them "smart".

Last year, it was a refrigerator that tweeted. This year, it's Wi-Fi-enabled laundry machines and fridges that can tell you when your groceries are going bad.

The washers and dryers, available starting in the spring, connect to any smartphone through a downloadable application. The phone can then be used as a remote control, so the machines can be turned on and off while their owner is at work or on the bus.

Samsung says it's not just something new — the app connection actually has some practical uses.

"If you started to dry clothes in the morning and forgot to take them out, you can go to your phone and restart your dryer for the time when come home, so your clothes are refreshed and ready to go." said spokesperson Amy Schmidt.

The company also says that with electricity rate (电价) varying depending on the time of day, more control over when the machines are used can help save money.

Perhaps, but what they will probably really accomplish is what all good technologies do — enable laziness. Rather than getting up to check on whether the laundry is done, users will instead monitor it on their phones while watching TV.

小题1: What can be inferred from the common response of the attendees at the CES?

A.The machine will be a big success.

B.their wives like doing the laundry.

C.The machine is unrelated to their life.

D.This kind of technology is familiar to them.小题2:We can conclude from Samsung's statements that ________.

A.the app connection makes life easier

B.it is better to dry clothes in the morning

C.smartphone can shorten the drying time

D.we should refresh clothes back at home小题3:What is the main idea of the last paragraph?

A.The laundry should be frequently checked

B.Lazy people like using such machines

C.Good technologies also cause problems

D.Television may help do the laundry

单项选择题