— Have you got the information ________ you need to use for the report?— Not yet. I'll try to find some on the Internet at once.
A:that
B:who
C:when
D:where
有指向标的地图,指向标箭头指向一般为( )
小明同学利用图所示的光具盘进行光的反射实验,让一束白光从左边斜射到平面镜上,多次改变入射的方向,他测得如下的数据:
实验次数
1
2
3
4
入射角
20°
30°
40°
50°
反射角