题目

—Do you regret paying twenty dollars for the dictionary?        —No．I ____ twice as much for it．        A．gladly paid            B．should gladly pay        C．would gladly have paid        D．had gladly paid 答案：C基因型为AaBb（两对等位基因位于两对同源染色体上）的小麦，用其花粉培养成幼苗，用秋水仙素处理，所有成体自交后代的表现型种类及比例为 [　　] A．1种，全部 B．2种，3∶1 C．4种，1∶1∶1∶1 D．4种，9∶3∶3∶1