you eat the correct foods be able to keep fit and stay healthy. A. Only if; will youB. O

问题补充：

you eat the correct foods be able to keep fit and stay healthy.

A. Only if; will you

B. Only if; you will

C. Unless; will you

D. Unless; you will

答案：

(答案→)A. Only if; will you

B. Only if; you will

C. Unless; will you

D. Unless; you will

解析：考查倒装句。Only放在句首，强调状语的时候，后面的主句使用部分倒装。本题only放在句首，强调条件句if you eat the correct foods。句意：只有你吃合适的食物，你才能保持健康。