my grandpa is very old,but he is_____good health.

题目

my grandpa is very old,but he is_____good health.
My grandpa is very old,but he is_____good health.
A.at B.in C.of D.on
请讲明原由,

答案

B.in表示处于某种状态,in good health也就是身体处于一种非常健康的状态,也就是我们常说的身体很好