工作中将电子剂量计佩带在在铅衣、纸衣、气衣或塑料衣的外面。
参考答案：错
We hadn't expected _____ so many people present at the meeting. [ ]
A. there being
B. there to being
C. there is
D. there to be
一条光线沿与镜面成30°角的方向射到平面镜镜面O点上，反射角为 ______度，若入射光线不动，镜面绕经过O点的轴线转动10°，则反射光线与入射光线之间的夹角为 ______度．
