A:He teaches very well.
B:He likes turtles.
C:He's friendly.
(2015•锦州)下列说法中正确的是( )
如图所示是有关电与磁实验的装置图,能用来探究影响电流的磁场强弱因素的是( )
实验室欲用NaOH固体配制1.0mol•L﹣1的NaOH溶液230mL: