问题 多项选择题

下面关于光板灵敏度和过载点的说法,正确的是()。

A.开局中,要求光板处测量到的“实际接收光功率”大于该光板的灵敏度指标值3dB,小于该光板的过载光功率指标值5dB;

B.光板接收灵敏度是在一定误码率情况下测得的,接收光功率在灵敏度附近,设备长期运行可能产生误码;

C.光接收灵敏度只和光板的收光模块有关,和光板的发光模块无关;

D.国标规定,S4.1光接口的过载点是0dBm。

答案

参考答案:A, B, C

单项选择题

请根据下面短文回答:
Open Time: 9:00 to 17:00 Tuesdays through Sundays(sales stop at 16:00)
Ticket Prices: Full Price: RMB 30; Half Price: RMB 15
Free invitation tickets are distributed every Wednesday and shall not exceed the approved quota. The corresponding policies are:
· 200 invitation tickets are freely distributed to the public every Wednesday.
· Visitors shall go to the bamboo courtyard on the first underground floor east to pick up invitation tickets according to the order of the telephone reservation from 8:30 to 11:00 a.m. every Wednesday.
· Staff of the museum will distribute the 200 free invitation tickets based on the order of the telephone reservation until the quota is used up.
· Visitors shall get the free invitation ticket by using their valid certificate.
Distribution is limited to per person.
· Visitors using the free invitation ticket cannot visit the special exhibitions.
Tickets are only valid on the date indicated.
Year-round Free Admission Policies.
· Retired people with the provision of their certificates of retirement
· Disabled people with the provision of their certificates of disability
· Disabled soldiers with the provision of their certificates of disability
· Staff working in the culture and museum systems with the provision of their employment certificates
· Children less than 120 cm in height and accompanied by adults (those without adult accompaniment will not be admitted and the accompanying adult must purchase a ticket as per regulations)
Routes:
Subway: Muxidi Station, Line 1
Buses: No.1, No.4 and Special Bus No.1 to the stop "Muxidi".
Reservation Telephone: 63370491 63370492

With free invitation tickets, you could visit______.
[A] all the exhibitions except for special ones in the museum
[B] all the exhibitions in the museum
[C] special exhibitions in the museum

单项选择题