— You should be on time tomorrow. There is no______ for being late again.
—OK, I will.
A:excuse
B: need
C:time
小明在探究“凸透镜成实像时像距与物距的关系”的实验中,所用的实验器材有:光具座、凸透镜、光屏和蜡烛等。
— _____