题目

You don't like popular music.Just keep on ___ it for a week and you will enjoy ___ it surely. A. hearing… listening   B. to listen… to hear   C. hear..listen    D. listening to..hearing 答案：D现有如下器材：弹簧测力计、盛有适量水的大杯子、一个铁块（能放入杯中）、细线、要测铁块的密度。主要步骤：①________②________铁块密度表达式：________