A: My library books are five days overdue .

B: Oh, will you have to pay a fine?

overdue a. 1. 过期的，到期未付的；2. 早该有的，迟到的，延误的

A: The bath is overflowing !

B: Oh no, I forgot that I had one running.

overflow vt. 1. 满得外溢，外流，泛滥；2. (with)充满，洋溢

vt. 淹没，从．．．中溢出，多得使无法容纳

n. 1. 容纳不下的物（或人）；2. 溢出，满出；3. 溢流口，溢流管

A: Excuse me. I couldn’t help but overhear , but I think I am the person you are looking for.

B: What a coincidence!

overhear vt. 无意中听到，偷听到

A: It is a shame that our holidays don’t overlap .

B: Indeed, I would love to go on holidays with you.

overlap v. 1.（与．．．）部分重叠；2. （与．．．）部分相同

n. 重叠，重叠的部分

A: Did you make it to the other side of the mountain?

B: No, the overpass was blocked.

overpass n. 天桥，立交桥

A: My comment overrides my previous statement.

B: You are always changing your mind.

override vt. 1. 不顾，不理睬，否决；2. 压倒，优先于

A: His dislike for me was overt .

B: Oh, he did not make it that obvious.

overt a. 公开的，不隐蔽的

A: I am planning to overthrow the government.

B: That is a big plan. you will need help.

overthrow  vt. 1. 推翻，打倒；2. 使终止，屏弃

n. 倾覆，终止，结束

A: Our car overturned when it hit the tree.

B: Was anyone injured?

overturn  vt. 1. 使翻转，使倾覆，使倒下；2. 颠覆，推翻

vi. 倾覆，翻转，翻倒

A: Were you surprised by the gift?

B: Yes, I was completely overwhelmed .

overwhelm  vt. 1. （感情上）使受不了，使不知所措；2. 征服，制服

A: I have an overwhelming need to sleep right now.

B: Well, what is keeping you from having a rest?

overwhelming a. 1. 势不可挡的，压倒的；2. 巨大的

A: What is that bird?

B: I think it is an owl .

owl. n. 猫头鹰

A: Is water a type of oxide ?

B: Yes, as it contains oxygen.

oxide n. 氧化物

A: Do you enjoy eating oysters ?

B: I have never tasted them.

oyster n. 牡蛎

A: Did you hear that the hole in the ozone is increasing in size?

B: Yes, it is a shame.

ozone n. 臭氧

A: You don’t seem to be arguing with your brother anymore.

B: No, we made a pact not to argue anymore.

pact n. 契约，协定，条约