481 once and for all =once and forever永远地 all at once 立即,马上 once in a while 立即,马上
once in a while 偶尔
for once 就这一次
482. by oneself 独自
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 ones opinion 按某人的看法
486. be opposed to 反对
487. be opposite to 与相反的
488. in order合适的,恰当的
in order 井井有条,处于良好状态; out of order出毛病,发生故障
489. made to order 定做的
490. originate in/from起源于,由..引起
491. on the outskirts 在城郊
492. oweto 把归于
493. on ones own 单独
494. of ones 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 舍弃,卖掉
498. participate in 参加
499. particular about 讲究,挑剔
500. in particular 特别是,尤其
下一篇: 考研英语的语法速成:谓语动词用单数的情况