391.improvement in表示原物有改进，好转
392.include……in把……列在……里面
393.inclusive of把……包括在内
394.independent of独立的，不受约束的
395.indicative of表明，说明
396.be indifferent to (=not interested in)对……漠不关心，冷淡，不在乎
397.(be) inferior to (=less good in quality or value)比……差;superior to比……好
398.inform sb. of sth.通知，告诉
399.be innocent of无罪的，无辜的
400.insist on (=order sth. to happen)坚持要
401.intend……for打算把……给
402.(be) intent on专心致志，坚决
403.instead of (in place of)代替，而不是……
404.in the interests of符合……的利益
405.instruct……in (=teach)教，指导，训练某人……
406.insure…… for把……保险(多少钱);ensure使安全;assure……(of)使……确信，保证
407.insure……against保险……以防
be interested in对……感兴趣
408.interfere in干涉，interfere with打搅，干扰
409.at intervals每隔一会儿，每隔一段距离
410.intervene in干预
411.invest in投资
412.be involved in (=become connected or concerned)卷入，参加
413.by itself (=alone， without help)单独地，靠自己
414.in itself本身;of itself自发，自然
415.be jealous of妒忌
416.jump at (=to be eager to accept)抢着接受，
417.jump on (=scold， tell of)叱责
418.junior to sb.年纪较……轻，职位较……低
419.(be) keen on喜爱，渴望
420.keep a close watch on (=keep a sharp lookout for)密切注视
421.keep……to oneself (=keep secret)不告诉别人
422.to (the best of) one‘s knowledge据……所知
423.at large (=at liberty， free)在逃，逍遥法外
at large (= in general) 一般来说，大体上
at large (= at full length; with details) 详细地
424.lean against(背)靠着……
425.at least 至少;at most 至多