seasonable: implies appropriateness to the season or being perfectly fitted to the occasion or situation: ~ weather.   （appropriate合适implies eminent and distinctive fitness十分合适，如a golf bag what was an appropriate birthday gift for a golfer对于高尔夫爱好者，送高尔夫球包作生日礼物十分合适）        又如seasonable temperatures/clothes/moment合时令的气温/衣服/适当的时机    occasion时间时机time or situation

timely: applies to what occurs or appears at the time or moment when it is most useful or valuable: a ~ warning.    又如timely arrival/reminder/rain/snow及时赶到/提醒/雨/瑞雪


well-timed: applies to what is so timely as to suggest care, forethought, or design: a ~ remark that stifled objections.    如he built the company through a string of well-timed acquisitions通过一系列时机恰到好处的并购，他建立了这家公司，如本例恰到时机的一句话


opportune: describes something that comes, often by chance, at the best possible moment and works to the advantage of those concerned: an idea that arose from an ~ remark.    又如he couldn't have arrived at a less opportune moment他当时来得太不是时候了，如the opportune use of humour to lower tension适时运用幽默来缓和紧张气氛


pat: may apply to what is notably apt, ready, or well-suited to the occasion: a ~ remark; OR to what is so very apt as to be suspect: offered an alibi that seemed too ~.    apt贴切，指语言精确得体，如a speech laced with some apt quotations演讲中包含了贴切的引用


seasonable合时令: 指合适的时间时机，timely及时: 表示在最有用处价值的时间出现，well-timed时间恰好: 指十分及时，以致让人想到事先精心计划，opportune时间恰好: 表示时间最有利最有利于成功，pat时间恰好: 表示时间时机十分恰好，或表示到了不自然不可信的地步


记忆方法: 1）首字母STWOP想成W我 + STOP停止<==适时停止

         2）适时的意思是在时间时机合适mean peculiarly appropriate to the time or situation.    situation情况，"合适的"情况即时机