He has breakfast night. That's a funny time breakfast.
A:at; for
B:at; in
C:in; for
D:in; at
____ ____ ____ ____ to live?
在一个种群中随机抽取一定数量的个体,其中基因型为AA的个体占26%,基因型为Aa的个体占70%,aa的个体占4%,在这个种群中,基因A和a的频率分别是: