题目

 Only when I left my parents for Italy _____ how much I loved them.         A. I realized   B. I had realized    C. had I realized    D. did I realize 答案：D盒子里共有3个白色球和1个黑色球，从盒子里任意摸一个球，摸到黑色球的可能性是 %，摸到白色球的可能性是 %．