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)

441. before long (=soon)不久, 过了不久以后.

442. in the long run (=in the end)从长远来说,最后; in the short term (从短期来说)

443. (be) at a loss 不知所措

444．major in 主修（某课程）

445. as a matter of fact 实际上, 事实是

446. by all means (=at all costs)不惜一切.

(=certainly) 当然行;by means of用…; by no means 完全不, 决不

447. on memory of 为纪念…

448. on the mend (=in the process of recovering) 好转, 在康复中

449. mention sth. to sb. 向某人提起某事

450. at the mercy of (=in the power of) 任…摆布, 在…支配下