The committee asked for these suggestions to be ______ on paper, so that they might study them further.

A．brought down

B．handed down

C．laid down

D．put down

如图所示，有两个相交成60°的平面镜，一束光线EO射到一个平面镜上，要使经过两镜反射回去的光线与EO重合，但方向相反，则EO与平面镜的夹角是（　　）

A．30°

B．60°

C．90°

D．45°