______ people went to the concert that was held in Reming Square _____ the night of May 25.
A:Two thousands, on
B:Many thousand, in
C:Thousands of, on
D:Several thousands of, in
如图所示,条形磁铁置于水平面上,当通电螺线管向左靠近条形磁铁时,条形磁铁仍保持静止,在此过程中条形磁铁受到的摩擦力的方向和大小( )
教材中“整式的加减”一章的知识结构如图所示,则A和B分别代表的是( )
台湾多发地震,是因为( )