坚持饭前便后洗手,这一做法在预防传染病上属于( )
A:杀死病原体
B:切断传播途径
C:控制传染源
D:保护易感人群
_____ your article carefully, some mistakes can be avoided.
The little girl was ______ frightened ______ move.
下列生物中能产生抗生素的是( )