问题 问答题

【问题2】
在该山区的行政机关的办公室内,按照GDMT最高速率标准上传一个45MB的文件至少需用多少秒时间(请简要写出计算过程)

答案

参考答案:

根据数据传输速率的计算公式将计算结果取整数为252秒(即4分12秒)

解析:

这是一道要求读者掌握ADSL宽带接入技术数据传输速率标准的计算题。本题的解答思路如下。

1)目前比较成熟的ADSL速率标准有①G.DMT和②G.Lite两种。其中,G.DMT标准是全速率的ADSL标准,支持高速下行速率为8Mb/s,上行速率为1.5Mb/s。该标准要求用户端安装POTS分离器,比较复杂且价格贵,比较适用于小型或家庭办公室。由此可知,试题中关键信息“按照G.DMT最高速率标准上传……”指的是G.DMT的上行数据传输速率R=1.5Mb/s。

另外,②G.Lite标准的下行速率为1.5Mb/s,上行速率为512kb/s,成本较低且便于安装,比较适用于普通家庭用户。

2)一个45MB的文件所包含的比特数D=45×210×210×8b=360×10242b。

3)按照G.DMT最高速率标准,设上传一个45MB的文件所用的时间为t。根据数据传输速率的基本计算公式[*]得:

[*]

将最后计算结果取整数为252秒,即按照G.DMT最高速率标准上传一个45MB的文件至少需用4分 12秒的时间。

阅读理解

Have you ever thought about what determines the way we are when we grow up? Remember the TV program Seven Up? It started following the lives of a group of children in 1973. We first meet them as wide-eyed seven-year-olds and catch up with them at seven-year intervals: nervous 14-year-olds, serious 21-year-olds and then grown-ups.

Some of the stories are inspiring, others sad, but what is interesting in almost all the cases is the way in which the children’s early hopes and dreams are shown in their future lives. For example, at seven, Tony is a lively child who says he wants to become a sportsman or a taxi driver. When he grows up, he goes on to do both. How about Niki? She says, “I would like to find out about the moon.” And she goes on to become a space scientist. As a child, soft-spoken Bruce says he wants to help “poor children” and ends up teaching in India.

But if the lives of all the children had followed this pattern, the program would be far less interesting than it actually was. It was the children whose childhood did not prepare them for what was to come that made the program so interesting. Where did their ideas come from about what they wanted to do when they grew up? Are children influenced by what their parents do, by what they see on television or by what their teachers say? How great is the effect of a single important event? Many film directors, including Steven Spielberg, say that an early visit to the cinema was the turning point in their lives. Dr. Margaret McAllister, who has done a lot of research in this area, thinks that the major factors are parents, friends and their wider society.

小题1:What does the text mainly discuss?

A.New ways to make a TV program interesting.

B.The importance of TV programs to children.

C.Different ways to make childhood dreams come true.

D.The influence of childhood experience on future lives.小题2: What does the underlined word “influenced” mean in the last paragraph?

A.Impressed.

B.Improved.

C.Affected.

D.Attracted.小题3: What are the examples in Paragraph 2 meant to show?

A.Many people’s childhood hopes are related to their future jobs.

B.There are many poor children in India who need help.

C.Children have different dreams about their future.

D.A lot of people are very sad in their childhood.小题4:Spielberg’s story is meant to show that _______.

A.going to a movie at an early age helps a child learn about society

B.a single childhood event may decide what one does as a grown-up

C.parents and friends can help a child grow up properly

D.films have more influence on a child than teachers do

多项选择题