O 
oath 
n.誓言, 宣誓, 诅咒 a solemn attestation of the truth or inviolability of one’s words 
obstacle 
n.障碍, 妨害物 something that impedes progress or achievement 
ominous 
adj.预兆的, 恶兆的 being or exhibiting an omen : PORTENTOUS. 
on the spot 
adv.当场, 在危险中, 处于负责地位 
operation 
n.运转, 操作, 实施, 作用, 业务, 工作, 手术 
option 
n.选项, 选择权 the power or right to choose : freedom of choice 
outlawe 
n.歹徒a lawless person or a fugitive from the law 
逃犯 a person excluded from the benefit or protection of the law 
v. 宣布...为不合法to deprive of the benefit and protection of law : declare to be an outlaw 
overlap 
v.(与...)交迭 to extend over or past and cover a part of 
overwhelm 
vt.淹没, 覆没 to cover over completely : SUBMERGE 颠覆,推翻UPSET, OVERTHROW