雅思词组1:on average按平均数计算;一般说来

Maybe you know that an adult in the UK will probably need about 1,700 kilocalories a day on average; someone in Antarctica will need about 3,500-just over double!
你们也许知道，在英国一个成年人平均每天可能需要1700大卡能量，在南极洲则需要3500大卡，是在英国时的两倍还多!

A:How many hours a day on average do you watch TV?
A:你平均每天看多长时间的电视?

B:Not a lot really...I should say just over an hour.
B:真的不是很多……应该是一小时多点儿。

above/below average表“在平均水平上/下”。

雅思词组2:on business因公

A:What about trains to London? I'll need to go there on business for one day.
A:能介绍一下去伦敦的火车吗?我需要去那出差一天。

B:Then you need to go to Central Station-that's for all the national services. There are regular trains to London.
B:你得去中央车站，那儿提供国内所有车次服务。有火车定点开往伦敦。

与business相关的常用表达:
in business经营;准备就绪
be the business很好
get about your business忙自己的事，做通常做的事
none of one's business与某人无关
out of business停业，歇业
business in busines公事公办

雅思词组3:on campus在校内

A:Are you familiar with the bus route of the downtown area?
A:你熟悉市中心的公交线路吗?

B:No, I am not at all because I have been living on campus.
B:不，一点儿也不熟悉，因为我住校。

雅思词组4:on display展出，展览，陈列

Samples of all the tools that were used widely at that time are on display in the showroom.
所有当时广泛使用的工具的样品都在陈列室展出。

雅思词组5:on hand现有(尤指帮助);在场，出席

Entertainment is laid on nearly every night with tour leaders on hand to organize lectures, games, quizzes and respond to any special requests from guests.
几乎每晚都有娱乐活动，领队会在场组织演讲、游戏和测试，并应对客人提出的所有特殊要求。

与hand相关的常用表达:
(at) first hand第一手;亲自
in hand在手头，可供使用;在控制中
out of hand难以(或无法)撞制
have one's hands fiat忙得不可开交
offone's hands不再由某人负责
to hand在手边，随时可得到

雅思词组6:on impulse一时冲动

A:I really didn't know you were looking for some new clothes.
A:我真的不知道你要买一些新衣服。

B:I just bought them on impulse last weekend.
B:上周末只是一时冲动才买的。

雅思词组7:on one's behalf为7…的利益，代表

We have a full-time accommodation officer available to help all students. She'll get in touch with you when you're accepted-she's got plenty of contacts in the town and will deal with the agencies on your behalf.
我们有一个全职的住宿管理员，她会给所有学生提供帮助。你被录取后她会和你联系，她在镇上有很多熟人，会代表你和中介打交道。

雅思词组8:on one's way to在去…的路上

A:I'm starving!
A:我饿了!

B:So am I.
B:我也是。

A:Actually, I was on my way to the canteen to get something for lunch.
A:事实上我正要去餐厅买午餐。

雅思词组9:on request应要求

The hotel can provide special services to guests on request.
该旅馆可以根据顾客的要求提供服务。

雅思词组10:on second thoughts经重新考虑，进一步考虑后，继而一想

A:What would you like? Pizza, sandwich, hot dog, filed rice, the canteen does everything...
A:你想要什么?比萨、三明治、热狗或是炒米饭，餐厅里什么都有……

B:Oh, something easy. Take-away fried rice sounds good.
B:要些简单的吧。可打包的炒饭听上去不错。

A:OK, fried...
A:好的，要炒……

B:No, on second thoughts, I'll have a cheese and tomato sandwich.
B:不，想了想，我还是要奶酪和番茄三明治吧。

相关词组:
have second thoughts改变想法，改变主意
without a second thought立即，马上，不假思索