人眼具有最大视敏度的彩色光的波长是（）
A．λ=380nm
B．λ=555nm
C．λ=680nm
D．λ=780nm
参考答案：B
用摆式仪测定路面抗滑性能时，重复5次测定的差值应不大于5BPN。
—______
—It's yellow.[ ]
A. What's this?
B. What color is it?
C. Spell it.
D. How are you?
