But it was previously unknown that many mentally handicapped people were subjected to the procedure.

但从前并不知道的是许多智力障碍的人们都接受这一手术。

youdao

But it was previously unknown that many mentally handicapped people were subjected to the procedure.

但从前并不知道的是许多智力障碍的人们都接受这一手术。

youdao