451. be in a mess 乱七八糟, 处境困难; make a mess of 弄乱, 打乱

　　452. bear(or keep)…in mind(=remember)牢记

　　453. bring(or call)to mind(=remember)使回想起

　　454. by mistake(由于粗心,健忘原因而)错误地

　　455. at the moment (=now) 此刻, 现在 for the moment (=for the time being)暂时; just a moment 稍等片刻;at the last moment 在最后一刻

　　456. in the mood for 有情绪去做..,有心境做.

　　457. no more…than 和…一样都不…

　　458. for the most part 多半,大多数,一般来说

　　459. at (the) most 最多, 至多

　　460. make the most of 充分利用

　　461. be not much of(=not a good)不是很好的...; be something of 有点…,像…

　　462. name after 用…的名字命名

　　463. native to 所产的

　　464. by nature 天生的, 生来

　　465. in mature 本质上

　　466. (be) in the nature of 属…性质

　　467. none other that 不是别人,正是…

　　468. above normal 高于正常(温度)

　　469. for nothing (=free, without payment)免费

　　470. nothing but 只有, 不过…而已

　　471. to say nothing of(=not to mention)更不用说…

　　472. do sth. at short notice 只给很少时间准备

　　473. until further notice 在另行通知前

　　474. take notice of (=pay attention) 注意

　　475. object to (=be opposed to) 反对

　　476. objection to (接动名词) 反对

　　477. on occasion(=now and then)不时地,必要时

　　478. by occasion of (=because of) 由于

　　479. occupy oneself with (in) 忙于(某事)

　　480. it occurs to sb. that… 某人想到…

　　481. once and for all =once and forever永远地; all at once (=suddenly, now) 立即,马上;once in a while (=occasionally) 偶尔;(just) for once 就这一次

　　482. (all) by oneself 独自(没有别人帮助)

　　483. operate on sb. 给某人做手术; operation n. come/ go into operation开始运转; put/bring sth. into operation 使…投产,运转

　　484. be of the opinion 持有…的看法

　　485. in one’s opinion 按某人的看法

　　486. be opposed to… 反对…

　　487. be opposite to 与…相反的

　　488. (be) in order(=acceptable)合适的,恰当的; in order 井井有条,处于良好状态; out of order(=in bad condition)出毛病,发生故障

　　489. made to order 定做的(衣服)

　　490. originate in/from(=begin)起源于,由..引起

　　491. on the outskirts (of) 在城郊

　　492. owe…to 把…归于…

　　493. on one’s own (=along, without help)单独

　　494. of one’s own某人自己的

　　495. keep pace with 跟…齐步前进

　　496. go to great pains=take pains 下功夫,努力

　　497. part with (=give up, sell) 舍弃,卖掉

　　498. participate in (=take part in)参加

　　499. (be) particular about 讲究,挑剔(吃,穿)

　　500. in particular (=especially) 特别是,尤其