“种瓜得瓜，种豆得豆”；“一猪生九子，连母十个样”，这些俗语反映了（    ）

A.生物能生长和繁殖               Ｂ.生物能对外界刺激作出反应

C.生物能适应环境并影响环境       Ｄ.生物具有遗传和变异的特性

— Well, Jane has many advantages, too.

— Oh, yes. _______ others are weak, she is strong.

A．If

B．When

C．Though

D．Where