数学分析（三册合并）徐森林

me.РA.on B.for C.to D.fromР答案:1~3CBDРin,within,by,until,till表示时间的用法与区别。Рin 表示“过…后”,用于将来时,也可用过去将来。РI’e back in a day or two.我过一两天就会回来。РThey finished the work in two hours.他们两个小时后就完成了工作。РI will be ready in a week.一周之后就准备妥当。Рwithin 表示“在…之内”,无时态限制。РHe will return within an hour.他将在一个小时之内回来。РI have seen her within these five days.在最近5天内我见过她。РHe live within five minutes’s walk.他住的地方走5分钟就到。Р3.by在…之前(时间),表示“动作完成期限”РWill you finish the task by tomorrow.你明天之前能完成任务吗?РWe should finish the work by six o’clock.我们必须在六点钟之前完成任务。РShe will be here by three..她最迟三点会来这里。Рuntil(till)表示动作“继续”,直到…为止。РThey watch TV until(till)twelve o’clock.他们看电视,直到12点。РUntil the last minute of the text ,we kept on writing our answer to the question.直到考试的最后一分钟,我们仍然坚持写问题的答卷。РHe had been in Beijing until(till) last week.他在北京一直待到上个星期。