近年来，托福、GRE、GMAT、研究生入学考试和其他各种英语等级考试，都倾向于单词范围越来越深广，难度越来越深，而词汇量不足，全盘都会受影响!突破难记易记的瓶颈，背单词要从根抓起;词根相同的一起背;词义相同的一起记!以下是小编整理的关于刘毅词汇22000 有关over的词群的资料，希望对你的词汇拓展有所帮助！

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。