It is necessary to remove the dirt and pathogenic bacteria, to avoid contaminating germ free or sanitizing articles and to avoid infection and cross-infection.
It is necessary to remove the dirt and pathogenic bacteria, to avoid contaminating germ free or sanitizing articles and to avoid infection and cross-infection.
答：除去手上的污垢及污染的致病菌，避免污染无菌物品或清洁物品，避免感染和交叉感染。