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【单选题】
传输网中使用的接收机一般收光功率范围是1280nm到1650nm，即接收机基本不分波长，这使收端单板互换成为可能。但我们平时使用光功率计测量光功率却有波长的选择项，是因为：（）。A.
光功率计使用特殊的接收机，有接收波长区别的接收机
B.
因为过来的光比较特殊，因此调整光功率计波长选择以示区别
C.
只是一个障眼法，其实不调整波长选择也可以测试到功率
D.
光功率计使用的接收机和传输网中接收机一致，在接收机前增加了一个滤波器，功率计上选择波长设置是进行滤波器带宽设置
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举一反三
【单选题】Who discovered the city of Derinkuyu? A. It was discovered by accident. B. It was discovered by an archeologist. C. It was discovered by a resident of Turkey. D. It was discovered by a police.
A.
It was discovered by a doctor.
B.
It was discovered by an archeologist.
C.
It was discovered by a resident of Turkey.
D.
It was discovered by a police.
【单选题】当时的局面很艰难,但她顺利地应付过去了。
A.
It was a hard situation, but she dealt with it unsuccessfully.
B.
It was a hard situation, but she dealt it successfully.
C.
It was a difficult situation, but she dealt with it successfully.
D.
It was an easy situation, and she dealt it successfully.
【简答题】党按照什么原则选拔干部？
【单选题】当时的局面很艰难,但她顺利地应付过去了。
A.
It was a hard situation, but she dealt with it unsuccessfully.
C.
It was a hard situation, but she dealt it successfully. C It was a difficult situation, but she dealt with it successfully. C It was an easy situation, and she dealt it successfully.
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