下列哪项检查对食管异物的确诊最重要？（） A.误吞异物病史 B.间接喉镜检查 C.纤

阅读理解。

     Miss Evans taught physics in a London school. Last month she was explaining to her class about

sound, and she decided to test them to see how successful she had been in her work. She said to them,

Now, I have a sister in Washington. If I was calling her on the telephone, and at the same time you were

20 meters away and listened to me from the other side of the street, who could hear what I said earlier,

my sister or you? And why?

    The cleverest boy at once answered, "Your sister, Miss Evans, because electricity (电) travels faster

than sound waves(波)." That's very good, Miss Evans answered, but then one of the girls put up her hand, and Miss Evans said, Yes, Betty?

     "I don't think so. Betty said, Your sister would hear you earlier because when it's eleven o'clock here,

it's only six o'clock in Washington."

1. Miss Evans was teaching her class ______.     

A. about sound                      

B. to hear some strange sound

C. about electricity                    

D. how to say time

2. She wanted to make her students know______.      

A. whether she could hear her sister in Washington

B. whether her students could hear her from 20 meters away

C. which was faster, London or Washington

D. electricity travels faster than sound waves

3. The cleverest boy thought that______.

A. sound waves travel faster than electricity

B. they would hear her sister in Washington first

C. Miss Evans's question wasn't right

D. Miss Evans's sister would hear her earlier

4. Miss Evans______.       

A. thought Betty's answer was much better

B. thought the cleverest boy's answer wasn't so good

C. was satisfied with what the girl had said

D. was satisfied with(对...感到满意) what the cleverest boy had said

5. Betty thought the cleverest boy was wrong, because______.

A. clocks in Washington showed a different time from those in London

B. electricity was slower than sound waves

C. they were only 20 meters away from the telephone

D. electricity travels as fast as sound waves

下列关于网络安全服务的叙述中，哪一个是错误的？A）应提供访问控制服务以防止用户否认已接收的信息B）应提供认证服务以保证用户身份的真实性C）应提供数据完整性服务以防止信息在传输过程中被删除D）应提供保密性服务以防止传输的数据被截获或篡改

以下哪项不属于客户对智能公交的需求（）

A.公交出行信息查询

B.公交乘客与车辆安全监控

C.公交公司具体工作安排查询

D.公交调度指挥与管理

报表类型不包括 ______。

A．纵栏式

B．表格式

C．数据表

D．图表式

供水管网如何划分？