光发送机输出光功率的稳定度要求为()
A..1%~5%
B.5%~10%
C.10%~12%
D.12%~15%
参考答案:B
There is a bus _____________.[ ]
A. every ten minutes
B. ten minutes
C. about ten minutes
油脂性基质栓应在()分钟内全部融化、软化,或触压时无硬心。
A.40
B.20
C.30
D.10
E.60