adj. 不必要的，没有用处的；

adj. 卵巢的，子房的；

[例句] ...a new treatment for ovarian cancer.

n. 装饰( ornament的名词复数 )，点缀，装饰品，首饰；v. 装饰，点缀，美化( ornament的第三人称单数 )；

[例句] ...a shelf containing a few photographs and ornaments.

[例句] ...Christmas tree ornaments.

v. 除去( obliterate的过去式和过去分词 )，涂去，擦掉，彻底破坏或毁灭；

[例句] Their warheads are enough to obliterate the world several times over...

[例句] Whole villages were obliterated by fire.

失去控制，失控，不受控制；

n. 实物教学课；

[例句] It was an object lesson in how to use television as a means of persuasion.

一经要求，点播；

在桌子上，被提交考虑，被提到桌面上，被搁置；

在移动中，在行动，在进步中，流动；

无法控制，立即，终于，难以收拾；

adj. 有义务的，必须的，有责任的；v. 使负有责任或义务（ obligate的过去式和过去分词 ）；

[例句] I felt obligated to let him read the letter...

[例句] He had got a girl pregnant and felt obligated to her and the child.

n. 牛，公牛(ox的复数)；

adj. 不寻常的，非传统的，不落俗套的；

[例句] She adores old, offbeat antiques.

[例句] ...a wickedly offbeat imagination.

v. 在…轨道上运行，环绕轨道运行( orbit的现在分词 )，沿轨道运行，绕转；

[例句] Mars and Earth have orbits which change with time...

[例句] The planet is probably in orbit around a small star.

安大略湖（北美洲中东部）（美国和加拿大共有的湖）；

n. 障碍物( obstruction的名词复数 )，阻碍物，阻碍，阻挠；

[例句] John was irritated by drivers parking near his house and causing an obstruction.

[例句] The boy was suffering from a bowel obstruction and he died.

adj. 价格过高的，定价太高的；v. 将…标价过高，索价过高（ overprice的过去式和过去分词 ）；

[例句] I went and had an overpriced cup of coffee in the hotel cafeteria...

[例句] Any property which does not sell within six weeks is overpriced.

n. 观察者( observer的名词复数 )，遵守者，观测者，目击者；

[例句] A casual observer would have taken them to be three men out for an evening stroll...

[例句] Observers say the woman pulled a knife out of the bunch of flowers and stabbed him in the neck.

n. 官场，官僚作风；

[例句] Officialdom has been against us from the start.

adj. 过热的；v. 使过热，变得过热( overheat的过去式和过去分词 )；

[例句] I think the reaction has been a little overheated...

[例句] In America, overheated drivers have been known to shoot each other.