Doing exercise every day ______ me pretty healthy.A．makes B．

makes
这里Doing exercise every day是主语
不定式短语、动词的-ing形式和名词性从句作主语,谓语动词用单数形式.
Doing experiments is a good way to find out answers to questions.做实验是找到问题答案的好方法.
To learn foreign languages is not so difficult as you think.学一门外语并不像你想象的那么难.
That I shall work with you is a great pleasure.我能和你在一起工作是极大的快乐.
但要注意：
what引导的主语从句,谓语动词通常用单数,但所指的具体内容是复数意义时,谓语动词可用复数形式.
What we want is more time.我们需要的是更多的时间.
What they need in that area are doctors and nurses.他们那个地区需要的是医务工作者.
What she left him are some old photos.她给他留下的是一些旧照片.

A

选A. 每日锻炼使我格外健康。
(Doing exercise every day)这件事情是主语，所以谓语用第三人称单数的makes.

选A