— Did you listen to the report last Friday?

— Yes, it was about the shortage of migrant workers. That was the first time I ____ about the subject. [ ]

A. heard

B. was hearing

C. would hear

D. had heard

“神舟”系列载人飞船的成功巡天，实现了炎黄子孙载人飞天的梦想．目前，我国科技工作者又在为实施登月计划辛勤地工作着．假如你是一名航天员，驾驶“神舟”号飞船到达月球上，请你探究下面的问题．

（1）根据下表所提的问题，设计相应的可在月球上进行的实验，在表格中简要写出实验方法．

①需要的实验器材有______．

②请你设计一个实验数据记录表格，画在下面的空白处．

③测得实验数据后，你如何判断物体受到的重力与质量是否成正比？