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【简答题】
一个622M光纤通信系统,系统中所采用激光器, 其标称波长为1310nm, 光脉冲谱线宽度λ<=2nm。发光功率为0 dBm。接收灵敏度为-28 dBm。光纤损耗为0.2 dB/Km,光纤色散系数D=1.8ps/km.nm,问系统所允许的最大中继距离是多少?
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【单选题】四显示自动闭塞的通过信号机显示一个绿色灯光时,表示运行前方最少有( )个闭塞分区空闲。
A.
B.
C.
D.
【单选题】The results of the medical checkup suggested that my father ______ in poor health, so the doctor suggested that he ______ smoking and take more exercise.
A.
was; gave up
B.
be; should give up
C.
should be; gave up
D.
was; give up
【单选题】According to the passage, the merger of United and Continental Airlines
A.
was initially suggested by the U. S. Justice Department.
B.
was identically approved by the both airlines' shareholders.
C.
is to follow the example of Delta and Northwest Airlines.
D.
will not become a reality until the formal vote on Sept. 17.
【单选题】(6)以下属于比亚迪秦的组合仪表显示信息的是( )。
A.
车速表、发动机转速表、燃油表、发动机冷却液温度表
B.
功率表、电量表、里程、能量流程图
C.
挡位、时间、室外温度、行车信息、故障提示信息
D.
以上都正确
【判断题】三显示自动闭塞区段机车信号机显示一个绿色灯光时表示准许列车通过,表示列车接近的地面信号为绿色灯光。
A.
正确
B.
错误
【多选题】以下属于比亚迪秦的组合仪表显示信息的是
A.
车速表、发动机转速表、燃油表、发动机冷却液温度表
B.
功率表、电量表、里程、能量流程图
C.
挡位、时间、室外温度、行车信息、故障提示信息
【单选题】以下属于比亚迪秦的组合仪表显示信息的是( )
A.
车速表、发动机转速表、燃油表、发动机冷却液温度表
B.
功率表、电量表、里程、能量流程图
C.
挡位、时间、室外温度、行车信息、故障提示信息
D.
以上都正确
【单选题】1)People with diabetes have too much sugar in their blood, so a drug that lowers blood sugar ought to be a good treatment, right? 2) Maybe not. Consider the diabetes drug Avandia, or rosiglitazone, wh...
B.
personal injury lawyers advertised on the Internet offering services for patients who thought they were injured by it
C.
F.D.A.responded quickly and banned the sale of the drug immediately
D.
the manufacturer issued a 'safety alert' telling patients to refer to their doctors
【单选题】In the last paragraph, the author describes the development of astronomy in order to
A.
suggest the potential discovery of celestial bodies by means of neutrino astronomy.
B.
illustrate the importance of surprises in making astronomic discoveries.
C.
demonstrate the effectiveness of the DUMAND apparatus in detecting neutrinos.
D.
name some cosmic phenomena that neutrino astronomy will illuminate.
【简答题】to give people ideas about what they should to is to sug______ v.
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