该研究使用食物频率问卷来追踪参与者每四年一次，关于多久一次，平均而言，每种水果他们所吃的量都是标准的。

The studies used food frequency questionnaires to follow up the participants every four years, asking how often, on average, they ate a standard portion of each fruit.

youdao

该研究使用食物频率问卷来追踪参与者每四年一次，关于多久一次，平均而言，每种水果他们所吃的量都是标准的。

The studies used food frequency questionnaires to follow up the participants every four years, asking how often, on average, they ate a standard portion of each fruit.

youdao