帮我看看这个倒装结构,还原下句子.
问题描述：
帮我看看这个倒装结构,还原下句子.
Only in the past 20 years have specialists in language study realize that signed languages are unique-a speech of the hand.
答
the specialists in language study have realized that signed languages are unique-a speech of the hand Only in the past 20 years