问题补充:
you eat the correct food be able to keep fit and stay healthy.
A. Unless; will you
B. Only if; you will
C. Only if; will you
D. Unless; you will
答案:
A. Unless; will you
B. Only if; you will
(答案→)C. Only if; will you
D. Unless; you will
解析:句意:只有如果你吃了适当的食物你才能保持健康。Only+状语从句放在句首的时候,句子用部分倒装,助动词will放在主语前面,unless“除非,如果不”,不符合句意。选C。