It is well known a person eats causes changes in the body.
A. what
B. that what
C. what that
D. that
网友回答
A. what
(答案→)B. that what
C. what that
D. that
解析：句意：一个人吃的东西会导致身体的改变这是众所周知的。这句话是It is well known that…句型，it是形式主语，that引导的是真正的主语从句，在that引导的主语从句中也有个主语从句，而且这个主语从句缺少宾语，用what连接，选B。