—I have a lot of trouble the newspaper.
A:What's wrong;reading
B:What's the matter;to read
C:What's matter;reading
D:What's the wrong;to read
如图所示,在一辆足够长的小车上,有质量为m1、m2的两个滑块(m1>m2)原来随车一起运动,两滑块与车接触面的动摩擦因数相同,当车突然停止后,如不考虑其它阻力影响,则两个滑块( )
菱形具有而一般平行四边形不具有的性质是( )