is very important for us to learn English well.
A:That
B:This
C:It
学完“摩擦起电”后,小明用与毛皮摩擦过的橡胶棒靠近悬挂着的塑料小球,发现小球被吸引,则小球 ____带电;若小球被排斥,则小球 ____带电.(一定/可能/一定不)