题图是小米手机的零部件世界采购图。此图反映出 A．中国的零部件质量最好 B．世

Some people can stay up all night and still get work done the next day.I'm not one of them.After a night without enough sleep, I feel badtempered.I have trouble remembering things.And all I want to do is to crawl into bed and sleep.

How do you feel after you've stayed up late to finish schoolwork? Or the day after an overnight party? Scientists now say that your answers to these questions may depend on your genes.

New research suggests that a gene called “period 3” affects how well you function without sleep.The “period 3” gene comes in two forms：short and long.Everyone has two copies of the gene.So, you may have two longs, two shorts, or one of each.Your particular combination depends on what your parents passed on to you.

Scientists from the University of Surrey in England studied 24 people who had either two short or two long copies of “period 3”．Study participants had to stay awake 40 hours straight.Then，they took tests that measured  how quickly they pushed a button when numbers flashed on screen and how well they could remember lists of numbers.

Results showed that the people with the short form of “period 3” performed much better on these tests than the people with the long form did.In both groups，people performed worst in the early morning.

After the first round of experiments，participants were finally allowed to sleep.People in the group that performed well on the tests (those with the short form of “period 3”) took about 18 minutes to nod off.

People with the long “period 3” gene, by contrast, fell asleep in just 8 minutes.They also spent more time on deep sleep.That suggests that people with the long form of the gene need more and deeper sleep to keep their brains working in top form.

I think I must have the long form of“period 3”．What about you?

小题1:The purpose of this passage might be________.

A．to tell us the importance of plenty of sleep

B．to tell the result of a research on sleepy gene

C．to inform the harm of lacking sleep

D．to announce the sleeping rules of humans小题2:Which of the following decides how well you perform without sleep?

A．One short form.

B．One long copy.

C．One short and two long copies.

D．Period 3.小题3:What kind of people need less sleep according to the research?

A．Those with two long copies of the gene.

B．Those with two short copies of the gene.

C．Those with one short and one long copy of the gene.

D．Those with three short copies of the gene.小题4:If one lacks enough sleep，one should avoid doing important or dangerous things ________.

A．at dawn

B．at night

C．in the afternoon

D．at noon

软件按功能可以分为：应用软件、系统软件和支撑软件(或工具软件)。下面属于应用软件的是______。

A．编译程序

B．操作系统

C．教务管理系统

D．汇编程序

小芳家有40 W的节能灯两个，25 W的白炽灯两盏，150 W的彩电一台，650 W的洗衣机一台，她家用的电能表上写着“220 V 5（10）A”字样。下面说法正确的是[ ]

A.小芳家的用电器同时使用时，总电流大于5A

B.小芳家的用电器不能同时使用

C.小芳家再购置一台1500 W的电暖气，所有的用电器还可以同时使用

D.为安全、方便地用电，小芳家应选用电流值稍大于10A就跳闸的空气开关

按逻辑功能区分，SIP系统由______、代理服务器、重定向服务器和注册服务器组成。

在超声波探伤中如何选择探头的频率？