象這種研究,百分之十幾的改變有意義嗎?“surveys every FOUR YEARS"

象這種研究,百分之十幾的改變有意義嗎?“participants filled out surveys every FOUR YEARS about what they ate and how much”,我連上個禮拜吃什麽都沒印象了,要是SURVEY, 就是隨便選。

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