胶面上沾有油类水分和灰尘不是开胶的重要原因。
参考答案:错
在同一点O抛出的三个物体,它们做平抛运动的轨迹如图所示.则三者做平抛运动的初速度vA、vB、vC的关系和三者做平抛运动的时间tA、tB、tC的关系分别是( )
A.vA>vB>vC,tA>tB>tC
B.vA=vB=vC,tA=tB=tC
C.vA<vB<vC,tA>tB>tC
D.vA>vB>vC,tA<tB<tC
—You like pop music, _______ you?
—Yes, very much. [ ]
A. aren't
B. don't
C. didn't
D. haven't