since+一段时间用什么时态Tom has taught us maths since 1982.例句,如题作简要分析
问题描述：
since+一段时间用什么时态
Tom has taught us maths since 1982.例句,如题作简要分析
答
都用完成时,完成时包括许多 since adv.(常用于现在完成时或过去完成时) 1.此后;从那时到现在 She left school three years ago and has worked as a nurse ever since.她三年前毕业,从那时起便一直当护士.2.之前,以...