下列选项属于可见光侦察的是（）。
A、望远镜
B、微光夜视侦察器材
C、雷达侦察
D、红外侦察
参考答案：A, B
一 Next Friday is my daughter's birthday.you know.
— Really? Then why don't you buy her _____ MP4 as _____ birthday present? [ ]
A. a; the
B. the; an
C. a; an
D. an; a
工件材料硬度高时选用油石研磨用：（）。
A、油石要软
B、油石要硬
C、油石粒度要粗
