生活离不开化学,下列生活习惯或做法合理的是( )
A:菜刀用后洗净擦干
B:废旧电池随意丢弃
C:霉变大米洗净后继续食用
D:尽可能多吃含微量元素的保健品
____是指亲子间的相似性;____是指亲子间和子代个体间的差异.
I don't think it is _____ useless competition, because it has offered us ____valuable experience for the next competition.