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【单选题】
以下关于FTP工作模型的描述中，错误的是（ ）。
A.
FTP协议使用控制连接、数据连接来完成文件的传输
B.
用于控制连接的TCP连接在服务器端使用的熟知端口号为21
C.
用与控制连接的Tcp连接在客户端使用的端口号为20
D.
服务器端由控制进程、数据进程两个部分组成
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举一反三
【单选题】Why does the author mention the history of tape recorders in the first paragraph?
A.
To inform. readers of new inventions.
B.
To lead into his following suggestion.
C.
To give an example of his suggestion.
D.
To show the importance of tape recorders
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【单选题】Why does the author mention the Massachusetts Bay Colony?
A.
The first lantern wicks were developed there.
B.
It was tile headquarters of the United States Lighthouse Board.
C.
Many of the tallest lighthouses were built there.
D.
The first lighthouse in North America was built there.
查看完整题目与答案
【单选题】今欲用H3PO4与Na2HPO4来配制pH = 7.2的缓冲溶液,则H3PO4与Na2HPO4物质的量之比n(H3PO4)∶n(Na2HPO4)应当是( ) (H3PO4的pKa1~pKa3分别是2.12,7.20,12.36)
A.
3:1
B.
1:1
C.
1:2
D.
1:3
查看完整题目与答案
【单选题】今欲用H3PO4与Na2HPO4来配制pH = 7.2的缓冲溶液,则H3PO4与Na2HPO4物质的量之比n(H3PO4)∶n(Na2HPO4)应当是(H3PO4的pKa1~pKa3分别是2.12,7.20,12.36)
A.
1:1
B.
1:2
C.
1:3
D.
1：4
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【单选题】下列文件中,数据量最小的是 ()
A.
一个分辨率为1024×768，颜色量化位数24位的BMP位图文件
B.
一个含100万字的TXT文本文件
C.
一段10分钟的MPEG视频文件
D.
一段10分钟的MP3音频文件
查看完整题目与答案
【单选题】下列文件格式中,数字音频文件数据量最小的是()
A.
MP3
B.
WAV
C.
MID
D.
WMA
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【简答题】在 Excel2010的单元格中输入18位身份证号前,需设置单元格格式为 ( )。A. 数字型 B. 日期型 C. 文本型 D. 常规型
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【单选题】Why does the author mention the 'mother' and 'father' in the first paragraph?
A.
to present the background of statistics in a humorous and understandable way
B.
to point out that parents can teach their children statistics
C.
to explain that there are different kinds of variables
D.
to introduce inferential statistics
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【单选题】脊髓损伤水平的评定,正确的是
A.
可主动曲肘,伸腕,但不能伸直肘关节,损伤水平定位C4
B.
确定损伤水平时,该节段关键性的肌肉肌力必须≥4级
C.
脐水平感觉减退,损伤水平定位T12
D.
主要以感觉损伤平面为依据
E.
乳房水平感觉减退,损伤水平定位T4
查看完整题目与答案
【单选题】Why does the author state in the first paragraph that observations are taken 'just once every twelve hours'?
A.
To indicate that the observations are timely.
B.
To show why the observations are of limited value.
C.
To compare data from balloons and computers.
D.
To give an example of international cooperation.
查看完整题目与答案
相关题目：
【单选题】Why does the author mention the history of tape recorders in the first paragraph?
A.
To inform. readers of new inventions.
B.
To lead into his following suggestion.
C.
To give an example of his suggestion.
D.
To show the importance of tape recorders
查看完整题目与答案
【单选题】Why does the author mention the Massachusetts Bay Colony?
A.
The first lantern wicks were developed there.
B.
It was tile headquarters of the United States Lighthouse Board.
C.
Many of the tallest lighthouses were built there.
D.
The first lighthouse in North America was built there.
查看完整题目与答案
【单选题】今欲用H3PO4与Na2HPO4来配制pH = 7.2的缓冲溶液,则H3PO4与Na2HPO4物质的量之比n(H3PO4)∶n(Na2HPO4)应当是( ) (H3PO4的pKa1~pKa3分别是2.12,7.20,12.36)
A.
3:1
B.
1:1
C.
1:2
D.
1:3
查看完整题目与答案
【单选题】今欲用H3PO4与Na2HPO4来配制pH = 7.2的缓冲溶液,则H3PO4与Na2HPO4物质的量之比n(H3PO4)∶n(Na2HPO4)应当是(H3PO4的pKa1~pKa3分别是2.12,7.20,12.36)
A.
1:1
B.
1:2
C.
1:3
D.
1：4
查看完整题目与答案
【单选题】下列文件中,数据量最小的是 ()
A.
一个分辨率为1024×768，颜色量化位数24位的BMP位图文件
B.
一个含100万字的TXT文本文件
C.
一段10分钟的MPEG视频文件
D.
一段10分钟的MP3音频文件
查看完整题目与答案
【单选题】下列文件格式中,数字音频文件数据量最小的是()
A.
MP3
B.
WAV
C.
MID
D.
WMA
查看完整题目与答案
【简答题】在 Excel2010的单元格中输入18位身份证号前,需设置单元格格式为 ( )。A. 数字型 B. 日期型 C. 文本型 D. 常规型
查看完整题目与答案
【单选题】Why does the author mention the 'mother' and 'father' in the first paragraph?
A.
to present the background of statistics in a humorous and understandable way
B.
to point out that parents can teach their children statistics
C.
to explain that there are different kinds of variables
D.
to introduce inferential statistics
查看完整题目与答案
【单选题】脊髓损伤水平的评定,正确的是
A.
可主动曲肘,伸腕,但不能伸直肘关节,损伤水平定位C4
B.
确定损伤水平时,该节段关键性的肌肉肌力必须≥4级
C.
脐水平感觉减退,损伤水平定位T12
D.
主要以感觉损伤平面为依据
E.
乳房水平感觉减退,损伤水平定位T4
查看完整题目与答案
【单选题】Why does the author state in the first paragraph that observations are taken 'just once every twelve hours'?
A.
To indicate that the observations are timely.
B.
To show why the observations are of limited value.
C.
To compare data from balloons and computers.
D.
To give an example of international cooperation.
查看完整题目与答案