Don't use words,expressions,or phrases____only to people with specific knowledge.A being knownB having been knownC to be knownD known为什么 还有D是现在完成时的被动语态吗?有人说：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。为什么that are 可以省略呢
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
为什么 还有D是现在完成时的被动语态吗?
有人说：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。
为什么that are 可以省略呢
答