401. instead of (=in place of) 代替，而不是…
402. instruct…in (=teach) 教.指导.训练某人…
403. insure…for 把…保险(多少钱); ensure 使安全; assure…(of) 使…确信,保证
404. insure…against 保险…以防
405. intend…for 打算把…给
406. (be) intent on 专心致志, 坚决
407. in the interests of 符合…的利益；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
426. (not) in the least 一点(也不), 丝毫(也不)
427. at one’s leisure 在…有空的时候
428. lend itself/themselves to适合于(某用途)
429. at length (=after a long time, at last)终于；at length (=in detail, thoroughly)详细地
430. go to any length想一切办法, 尽一切力量
431. be liable to (=be subject to)易于..的,应受(罚)
432. be liable for 对…应负责任的
433. lie in 在于
434. in life 一生中
435. for life 终身
436. in the light of (=considering; taking into account) 考虑到, 根据
437. throw light on ( = make clear, explain) 使…更为清楚, 提供线索, 阐明
438. in line with(=in agreement with)符合,一致
439. long for(=want very much)渴望,希望得到
440. for long 很久,很长时间(否定句.疑问句中)