题目

一个基因型为AaBb的精原细胞和一个同样基因型的卵原细胞，按自由组合定律遗传，各自经减数分裂产生的精、卵细胞的数目和种类数分别是(  ) A．2个、1个和2种、1种                 B．4个、4个和2种、2种 C．4个、1个和2种、1种                 D．2个、2个和2种、2种 答案：CThe old teacher was honoured by the Party ________ his unselfish contributions ________ people in the railway mountain areas.A.for, forB.to, toC.for, toD.by, for