单项选择题当电荷在一个横截面可以忽略的细线中运动，或者电荷束的横截面可以忽略时，可以把电流看作在一根无限细的线上流动，为线电流。（ ）A.对B.错
单项选择题Ichabod Crane falls in love with Katrina, a farmer’s daughter, because he is attracted to her beauty and personality. A、正确 B、错误
