Group21 Ob-against, over
“对抗；超越”
obstacle
n. 障碍　
If we beat Central High tomorrow, we shall have removed the last obstacle between us and the championship.
如果我们明天击败中央中学，便扫除掉我们与冠军之间的最后障碍。
obliterate
vt. 消除；擦掉　
Today's rain has completely obliterated yesterday's snow;not a trace remains.
今天下的雨把昨天的积雪完全除去，一点也不留。
obsess
vt. 困扰；萦绕
The notion that she had forgotten to lock the front door obsessed mother all through the movie.
在看电影的时候，忘了锁前门的想法一直萦绕着妈妈。
obstruct
vt. 阻碍　
The disabled vehicles obstructed traffic until removed by a tow truck.
抛锚的车子直到被拖车拖走后才不阻碍交通。
obtrude
vt. 强行提出　
It is unwise for an outsider to his opinions into a family quarrel.
局外人硬把自己的想法加入一场家庭争论中是不智的。
obviate
vt. 排除；避免　
By removing her hat, the lady in front obviated the need for me to change my seat.
前座的小姐脱掉她的帽子，使我不必换座位。