众里寻他千百度。 ，娜人却在， 。（辛弃疾《青玉案》）
关于下列装置的说法正确的是（ ） A．装置①中盐桥内的K+移向CuSO4溶液 B．装置①将电能转变为化学能 C．若装置②用于铁棒镀铜，则N极为铁棒 D．若
命题，命题，则是的 ( ) A．必要不充分条件 B．充分不必要条件 C．充要条件 D．既
一个质点,初速度的大小为2 m/s,末速度的大小为4 m/s,则( ) A.速度改变量的大小可能是6 m/s B.速度改变量的大小可能是4 m/sC.速度
Among all the fast growing science and technology, the research of human genes, or biological engineering as people call it, is drawing more and more attention now. Sometimes it is a hot topic discuss
如图13-1-4所示，矩形线框的匝数n=250匝，ab=12 cm,ad=10 cm，线框置于B=T的匀强磁场中绕垂直于磁场的轴以120 r/min匀速转动，线框通过滑环与外电路相连，外
When he saw all his books _____ here and there on the floor, he knew that something terrible _____. A. lying; must have happened B. lie; must happen C. lay; might have happened D. had lain; cou
的解集为______________.
