开了一整天会我的头脑变迟钝了.My head became heavy after a whole day's meeting.不要让你的脑子在假期里变迟钝.Don't let your mind rust during the vacation.观众的头脑变迟钝了.The mind of the audience is becoming dulled....

“变迟”的英语可以翻译为：laten ...