be unable to find out meaning in Chinese
无从知道
Examples
- His parents thought he was dumb . they took him to a doctor , but were unable to find out the reason why he wouldn t speak . no matter what they tried , he did not say anything
一个小孩，他从小到七岁没有讲过一句话，父母都认为他是哑巴，带他去看医生也找不出理由，试什么办法还是不会讲话。