Don't use words,expressions,or phrases____only to people with specific knowledge.

问题描述:

Don't use words,expressions,or phrases____only to people with specific knowledge.
A being known
B having been known
C to be known
D known

D
其实这个句子写成定语从句,是这样:Dont't use words,expressions,or phrases that are known only to people with specific knowledge.
我们可以把that are 省略,就是选d了