调查作业：了解你所在小区家庭5月份用气量情况：

  小天、小东和小芸三位同学住在同一小区，该小区共有300户家庭，每户家庭人数在2﹣5之间，这300户家庭的平均人数均为3.4．

  小天、小东和小芸各自对该小区家庭5月份用气量情况进行了抽样调查，将收集的数据进行了整理，绘制的统计表分别为表1，表2和表3．

表1 抽样调查小区4户家庭5月份用气量统计表  （单位：m³）

表2 抽样调查小区15户家庭5月份用气量统计表 （单位：m³）

表3 抽样调查小区15户家庭5月份用气量统计表 （单位：m³）

根据以上材料回答问题：

小天、小东和小芸三人中，哪一位同学抽样调查的数据能较好地反映该小区家庭5月份用气量情况，并简要说明其他两位同学抽样调查的不足之处．

电力公司为鼓励市民节约用电，采取按月用电量分段收费的办法，已知某户居民每月应缴电费y(元)与用电量x(度)的函数图象是一条折线(如图)，根据图象解答下列问题．

根据短文理解，完成下列各题。

   My mother was telling me about how she and her family got their first television when she was a teenager. Of course, it was black and white. She said she only watched it at night. When I was young, we had only about 3 or 4 different channels. My brothers, my sisters and I would sometimes fight about which channel to watch. But we usually enjoyed the same shows.

   Nowadays, we can get hundreds of channels on TV. There are channels with old movies, cooking, fishing and so on. It's amazing! I wonder how much my brothers, my sisters and I would fight if we had hundreds of channels when I was a child. Of course, we had only one television set. These days I notice families with 2 or 3 or more television sets in their homes. I guess it stops people from arguing over which channel to choose.