题干
The writer his home town and worked for a newspaper.
A：leave
B：leaves
C：leaving
D：left
答案(点此获取答案解析）
D
The writer his home town and worked for a newspaper.
A：leave
B：leaves
C：leaving
D：left
行入射到三棱镜上，经棱镜折射后，交会在屏上同上点，若n1和n2分别表示三棱镜对红光和蓝光的折射率，则有：（ ）