下面是色散补偿单模光纤的是（）。
A、SMF
B、MMF
C、DCF
参考答案：C
Does your pen pal live in Beijing? [ ]
A. She is from USA.
B. She likes reading.
C. Yes, she does.
D. She can do the dishes.
为了防止表面划痕，精密磨削选择砂轮特性为（）
A.WAF100K
B.WAF100L
C.WAF100J
