如图所示,放在马蹄形磁铁两极之间的导体棒ab,当通有自b到a的电流时受到向右的安培力作用,则磁铁的上端是________极.
N
根据左右定则,可得磁铁的上端为N极,
What had previously been regarded as ______ property was made collective in the Land Reform
Movement. [ ]
A. personal
B. individual
C. own
D. private
冰冻红细胞的解冻应放入()恒温水浴箱中,轻轻振动使其快速融化。
A.4±2℃
B.37℃~40℃
C.22±2℃
D.2℃~8℃