请结合材料回答下列问题: (1)上述图表中的数据说明了什么问题? ________________________________________________________________________________________________________________________________________________________________________________________ (2)假如让你参与调查,你还会采用哪些调查方法?(至少两种) ________________________________________________________________________________________________________________________________________________________________________________________ (3)针对图表中反映的问题,结合教材知识,请你提出改进意见。(至少两条) ________________________________________________________________________________________________________________________________________________________________________________________ |