A:30°
B:45°
C:60°
D:90°
如图所示,OD为反射光线,ON为法线。请画出反射光线OD的入射光线。
下列物质的化学式书写不正确的是( )
make up one's mind; give in; ever since; be fond of; grow up: on schedule; change one's mind ;care about; prefer to; get sb. interested in
根据问题填空: