A: What type of tree is that?
B: I think it is an oak tree. It is certainly large enough to be one.
oak
n. １．栎树，橡树；２．栎木，橡木
A: Oh no, I’ve dropped an oar .
B: We will have to swim to the shore now.
oar
n.　桨，橹
A: Please tell me the big secret.
B: Sorry, I took an oath and swore that I wouldn't.
oath
n.　１．誓言，誓约；咒骂，诅咒语
on / under oath　 在法庭上宣过誓
A: My pupils are so obedient , they always do their home work.
B: You are lucky, mine are terrible.
obedient
a.　服从的，顺从的
A: Robert told an obscene joke last night.
B: Is it too rude to repeat to me?
obscene
a.　１．淫秽的，下流的；２．可憎的，可恶的
A: Did you understand the theatre performance?
B: No, it was too obscure for me.
obscure
a.　１．不著名的，不重要的；２．费解的，模糊不清的；３．隐藏的，偏僻的
vt.　使变模糊，掩盖
A: You are always playing video games.
B: I know. I have an obsession.
obsession
n.　困扰，无法摆脱的思想（或情感）
A: Excuse me, but your car is obstructing the entrance to my home.
B: Oh, I’ll move it right away.
obstruct
vt.　１．阻塞，堵塞；２．阻碍，阻止，妨碍
A: Can I move into the apartment today?
B: No, you can have occupancy next week.
occupancy
n.　占有，使用，居住
A: What is that terrible odour ?
B: Oh, sorry, it must be my socks.
odour
n.　气味
A: Beverley looked stunning at the party.
B: Yes, her outfit was offset by her jewelry.
offset
vt.　补偿，抵消
A: Do you have any offspring ?
B: Yes, I have three daughters.
offspring
n.　１．子女，子孙，后代；２．（动物的）崽
A: Do you like olives ?
B: Yes, especially black ones in salad.
olive
n.　橄榄，橄榄树
A: Is that glass clear?
B: No, it is opaque , that is why you are having difficulty seeing through it.
opaque
a.　１．不透明的，不透光的；２．难理解的，晦涩的
A: Women in the old days were frequently oppressed by their husbands.
B: I am glad that times are changing.
oppress
vt.　１．压迫，压制；２．使（心情等）沉重，使烦恼
A: You would like the blue car?
B: No, I think I’ll opt for the red one.
opt
vt. (for)　选择，挑选
A: The weather will be wonderful tomorrow.
B: You are always filled with optimism .
optimism
n.　乐观，乐观主义
A: I study at my optimum between eight and ten in the morning.
B: Oh, I work best in the evenings.
optimum
a.　最合适的，最优的，最佳的
A: Where did you get the apples?
B: I picked them in the orchard down the road.
orchard
n.　果园
A: I was in a serious car accident last year.
B: That must have been a terrible ordeal .
ordeal
n.　苦难经理，折磨，煎熬
A: I love studying science.
B: I orient more towards the Arts.
orient
vt.　１．使适应，使熟悉情况（或环境等）；２．（to ,toward）使朝向，以．．．为方向（目标）
n.　东方，亚洲（尤指远东），东半球
A: Oriental cuisine is my favourite.
B: Yes, I also love Chinese food.
oriental
a. 东方的，东方人的，东方文化的
A: I was unable to find my orientation in the city.
B: You should have carried a map with you.
orientation
n.　１．方向，目标，方位；２．熟悉情况，适应，情况介绍
A: From where does the guitar originate ?
B: Well, there are many types of guitar, so probably many countries.
originate
vi. (in,from,with)　起源于，来自，产生
vt.　创造，创始，开创
A: That is a beautiful ornament beside the TV.
B: Thanks, it was a gift from a friend.
ornament
n.　１．装饰品，点缀品；２．装饰，点缀
vt.　装饰，点缀，美化
A: I was an orphan until the age of seven.
B: Goodness, do you know what happened to your parents?
orphan