题目

Our teacher work very hard. They get up early in the morning and work very（A）______. How to help our teacher ?First, we must try to （B）learn our subjects well to make our teachers spend less time on us and let them have more rest.Second, we must clean the blackboard and the teacher’s desk very （C）______. If we can do so, our teachers will work better and of course they will be happier.Our teachers often have to speak for a long time and they are very tired. At this time, （D）it is better for us to bring them some water. When our teachers drink the water, they will speak （E属于条件反射的是（ ）A．膝跳反射B．眨眼C．谈虎色变D．呼吸