DNA分子在聚丙烯酰胺凝胶电泳中泳动的速度取决于片段的大小。

A．思维定式
B．思想碰撞
C．心不在焉
D．思维闭塞

A．the resistance exhibited due to the inherent properties of the bacterium
B．Bacteria acquire resistance genes from outside
C．Drug resistance caused by abuse of antibiotics
D．Drug resistance acquired by bacteria during transmission