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，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
大体上 at large(=at full length;