题目

—I didn't do well in the exam yesterday.Of course I      for it.   —Oh,you poor fellow! But I think you should learn a lesson.     A.hadn't studied    B.haven't studied C.wasn't studying   D.wouldn't study   答案：A往浅绿色的Fe（NO3）2溶液中逐滴加入稀盐酸后，溶液的颜色应该是（　　）A．颜色变浅B．逐渐加深C．没有改变D．变棕黄色