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【单选题】
以下关于SDH速率体系基本概念的描述中,错误的是A.
SDH定义了三种速率：SONET的STS、OC速率标准、SDH的STM标准
B.
OC定义的是光纤上传输的光信号速率
C.
SONET定义的电信号速率标准是以T1为基础的
D.
对应于STS1的是第1级OC-1
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【判断题】Arthur Dimmesdale often talked about the sickness of his soul, but Chillingworth refused to listen.
A.
正确
B.
错误
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A.
result in
B.
result from
C.
carry away
D.
take away
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【单选题】Most sickness often ____ from eating and drinking too much.
A.
results of
B.
results from
C.
results in
D.
is resulted
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