Very often when we see young people sitting there，looking at the screen of a mobile phone and smiling，we may think nothing is wrong.But when we come to the question "how much time do they actually spend on media daily？"，the answer is surprising：young people spend about nine hours every day using media，and this only includes media used for enjoyment.
   Today's young people seem to have become crazy multitaskers.They often use media when doing other activities.Some watch TV when doing homework，some text，and some others listen to music.But what do young people think of this？A research showed that two thirds of them believed watching TV or texting had no influence on schoolwork.Half of them thought using social media made no difference.However，researches have given a different answer： "media multitaskers" did worse in tests.
   Scientists did a research among more than 400 students.It shows that those who text a lot have more trouble sleeping and do worse in their study.In another research，students who didn't text during a lesson took down a lot more notes than those who were texting.A similar research also found that students who texted when doing schoolwork had lower overall（總體的）grades.
   According to a research，if a kid uses social media a lot especially at night，he or she will sleep worse and feel more nervous and depressed.On the one hand，young people stay up late to check messages and information.They may also be woken up by messages they receive.On the other hand，even the light from a screen could influence their sleep.Some other researches also show that children who use media at night go to bed later，get fewer hours of sleep each week，and            .

（1）The answer to the question in Paragraph 1 is surprising because young people

A

A

.
A．spend about 9 hours on media for fun daily
B．often look at their mobile phones and smile
C．use different kinds of media to relax themselves
（2）The underlined word "multitaskers" in Paragraph 2 refers to people who

C

C

.
A．ask a lot of questions
B．have several mobile phones
C．do several tasks at the same time
（3）Which of the following can be put into the

B

B

？
A．do better in their study
B．become sleepy more easily during the daytime
C．feel less nervous and much happier the next day
（4）What is the passage mainly about？

B

B

A．Social media is very popular among young people.
B．Using media too much has a bad influence on young people.
C．The use of social media has both advantages and disadvantages.