现代文物分析技术与传统文物研究的信息来源有何不同。

半径为5的球的表面积和体积分别为______、______．

阅读理解。

     I've always known my kids use digital communications gear (装置) a lot. But my cellphone

bill last month really grabbed my attention. My son had come up to nearly 2,000 incoming text

messages, and had sent nearly as many. Of course, he was out of school for the summer and

communicating more with friends from a distance. Nevertheless, he found time to hold down a

summer job and complete a college course in between all that typing with his thumb.

     I was even more surprised to learn that my son is normal. Teenagers with cellphones each

send and receive 2,272 text messages a month on average, Nielsen Mobile says.

     Some experts regret that all that keyboard jabber is making our kids stupid, unable to read

nonverbal cues such as facial expressions, gestures, posture and other silent signals of mood

and attitude. Unlike phones, text messaging doesn't even allow transmission of tone of voice or

pauses, says Mark Bauerlein  author of a book called The Dumbest Generation: How the Digital

Age Stupefies Young Americans and Jeopardizes (危害) Our Future.

     Beyond that, though, I'm not sure I see as much harm as critics of this trend. I've posted before

on how I initially tried to control my kids' texting. But over time, I have seen my son suffer no

apparent ill effects, and he gains a big benefit, of easy, continuing contact with others.

     I don't think texting make kids stupid. It may make them annoying, when they try to text and

talk to you at the same time. And it may make them distracted, when buzzing text messages

interrupt efforts to noodle out a math problem or finish reading for school.

     But I don't see texting harming teens' ability to communicate. My son is as accustomed to

nonverbal cues as any older members of our family. I have found him more engaged and easier

to communicate with from a great distance, because he is constantly available via text message

and responds with faithfulness and speed.

1. What does the underlined word "distracted" in the fifth paragraph mean?

A. Confused.                          

B. Absentminded.

C. Comfortable.                        

D. Badtempered.

2. What would be the best title for this passage?

A. For Teens, Texting Instead of Talking              

B. For Parents, Caring Much for Their Kids

C. Advantages and Disadvantages of Texting            

D. The Effect of Communication

3. What is Mark Bauerlein's attitude towards texting?

A. It is so convenient for teens to communicate with others.

B. It is likely to cause trouble in understanding each other.

C. It is convenient for teens to text and call at the same time.

D. It will cause damage to the development of intelligence.

4. The author's attitude towards texting is ________.

A. suspicious                  

B. opposed

C. supportive                  

D. doubtful

5. According to the passage, which of the following statements is NOT true?

A. It is normal for a teen to send or receive 60 text messages a day.

B. Texting is a very popular way of communication among teens.

C. Parents don't mind teens' texting and talking at the same time.

D. The writer limited his son to sending or receiving text messages at first.

监理单位对同类工程采用新材料、新工艺、新设备、新技术和实际效果及存在问题的相关信息采集，宜在( )阶段进行。

A．项目决策阶段

B．设计阶段

C．施工招标阶段

D．施工阶段

噎膈的症候特征是（）

A.胸骨后不适 

B.进食时有停滞感 

C.继则咽下梗噎 

D.甚至不得入 

E.食入即吐

品种