I think this is a good way to keep healthy.(改为否定句)

题目

I think this is a good way to keep healthy.(改为否定句)
I __________ think this _________ a good way to keep healthy.

答案

I (don't ) think this (is) a good way to keep heathy.
我不认为这是保持健康的好方法=我认为这不是保持健康的好方法.