1.(2017·全国卷Ⅰ)Fast food is full of fat and salt; by ________ (eat) more fast food people will get more salt and fat than they need in their diet.
【解析】考查动词ing作介词宾语。在介词about，before，after，for，with，by等之后作宾语应该用动词ing形式，故用eating。
【答案】eating
2.(2017·全国卷Ⅱ)This included digging up the road, ________(lay) the track and then building a strong roof over the top.
【答案】laying
3.(2017·全国卷Ⅰ)They are required ________(process) the food that we eat，to recover from injury and for several other bodily functions.
【解析 ...