the best thing to do is figure out the type of foot you have and how you walk.该句子中的the best thing to do is figure out.......be动词后面可以接动词原形吗?是不是应该加个to在is的后面啊?变成 is to figure out..
书上没有加哎,书上印错了吗?
是什么书,你可以拍照上传看一下