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问题 单项选择题

MP3是一种广泛使用的数字声音格式。下面关于MP3的叙述中，不正确的是______。

A．MP3声音是一种全频带声音数字化之后经过压缩编码得到的

B．MP3声音的码率大约是56Kbit/s左右，适合在网上实时播放

C．MP3声音的质量接近CD唱片声音的质量

D．与MIDI相比，表达同一首乐曲时它的数据量比MIDI声音要大得多

答案

参考答案：B

阅读理解

D
Cost of American Wars
War name
Cost of the war
Cost as a percent of annual GDP
Revolutionary War
US $ 2.2 billion (in 2002 dollars)
63%
War of 1812
US $ 1.1 billion
13%
Mexican War
US $ 1.6 billion
3%
Civil War
US $ 62 billion
104%
Spanish American War
US $ 9.6 billion
3%
World War I
US $ 190. 6 billion
24%
World War II
US $ 2.9 trillion
103%
Korean War
US $ 335.9 billion
15%
Vietnam War
US $ 494.3 billion
12%
First Gulf War
US $ 76.1 billion
1%
Notes: ① GDP → 国民生产总值
② 1 billion =" 1,000,000,000             "      ③1 trillion = 1,000,000,000,000
69. Which wars cost more than a year’s worth of the GDP?
A. First Gulf War and World War I                           B. The Civil War and World War II
C. World War II and Revolutionary War                    D. Mexican War and Civil War    
70. The American annual gross domestic product in 1951 was _________.
A. 2.239 trillion            B.2.9 trillion          C. 3, 25 trillion      D. 76.1 billion 
71. Which of the following is NOT true?
A. Mexican War cost more than War of 1812.
B. First Gulf War cost the least in term of the percentage of the annual of GDP.
C. World War II cost more than Korean War.
D. Mexican War cost as much money as Spanish American War. 
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多项选择题

OC曲线的数值(接收概率L(p))可通过( )获得。

A．正态分布计算

B．二项分布计算

C．查GB/T 2828.1—2003表获得

D．查GB/T 2828.2表获得
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