下列不属于可遗传的变异的是[ ]
A.玉米中出现白化苗
B.高茎豌豆的后代出现矮茎个体
C.色觉正常的夫妇生下色盲儿子
D.干旱环境中水稻结出的种子比较
答案:D
若不等式a<2x-x2对于任意的x∈[-2,3]恒成立,则实数a的取值范围为________.
______n (N) umber of students went to visit that school last Sunday. [ ]
A. The
B. A
C. An
D./