——__________?
——It was nice and interesting.
A:Where did you go on vacation
B:When did you go on vacation
C:How was your vacation
D:Did you enjoy your vacation
对美国“硅谷”的评价正确的是( )
下列现象与物理知识相对应的是()
如图所示的现象中,属于光的反射现象的是( )