—Would you mind _______ the answer on the blackboard, sir? We can't follow you.
—OK, I'll do it now.
一枚导弹的价格再跌,也不会比一个茶叶蛋低;一个茶叶蛋的价格再涨,也不会比一枚导弹的价格高。商品的价格不会无限波动,决定因素是( )