为了减少噪声对工作场所和附近居民的影响,在距高压电器( )处连续性噪音水平不应大于85dB。
A.1m B.1.5m C.2m D.2.5m
参考答案:C
It was_______ that thousands of people saw it. [ ]
A. such an exciting film
B. a very exciting film
C. too excited a film
D. so excited an film
激光的特点以下哪一项有误()
A.方向性强
B.相干性好
C.穿透性强
D.单色性好
E.极化性高