Lecture8双关、轭式搭配-PPT课件

22
Important words and expressions
• Imperative: (adj)必要的； • It is imperative to meet face to face with
the client.
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本节课的主要目标 (the main objectives of the class)
• Tangible assets • Tangible net worth? • 有形净值
21
Important words and expressions
• Para 6: • Liabilities: (n) (legal responsibility for
something; especially for paying money that is owed, or for damage or injury);债务 • Long-term liabilities • 长期债务； • Current liabilities: • 短期债务（流动债务）
• Estate: (a place for someone to live)
20
Important words and expressions
• Tangible: (adj) if someone is tangible, you can touch or feel it; (有形资产) 有形资产？
• 美国大陆东起大西洋西至太平洋，横跨 4500公里。北与加拿大接壤，南与墨西哥 与墨西哥湾毗邻。
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• It is important to be certain that (the company you are intending to establish a relation with is reputable) and the usual practice to do so is to run a business background check.

21. give thanks for 22. at this time 23. have a big meal 24. main dish 25. fill ... with ... 26. cover ... with ... 27. serve sth to sb 28. at a high temperature 29. one by one 30. place ... on ...
26.Thanksgiving day 27.traditional adj. tradition n. 28.autumn\fall----spring-------summer------winter 29.traveler n.
travel v. travel to SW 30.celebrate V. celebration n. 31.mix V. mix up 混合 ，混淆
Eg: Let us stay here, will/ won't you? 请（你）让 我们留在这好吗？
4. 祈使句的回答。
祈使句的动作通常是表示将来发生的动作，所 以回答祈使句时，一般用will或won’t。
语法练习
• 1._______ late again, Bill! A. Don't to be B. Don't be C. Not be D. Be not • 2. _______ cross the road until the traffic lights
5.常见的不可数名词
1.food 4.tea 7.fruit 10.knowledge 13.coke 16.chicken 19.friendship 22.room 25. Meat
2.fish 5.drink

f g={<a1,c1>,<a2,c2>,<a3,c2>}
g:B→C 和 f g:A→C是满射的, 但 f:A→B不是满射的.
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反函数
反函数存在的条件 (1) 任给函数F, 它的逆F 1不一定是函数, 只是一个二元关系. (2) 任给单射函数 f:A→B, 则f 1是函数, 且是从ranf 到A的双
Z： 0 1 1 2 2 3 3 …
↓ ↓↓↓↓ ↓ ↓
N： 0 1 2 3 4 5 6 …
这种对应所表示的函数是：
f：Z
N,
f
(x)
2x 2x
1
0 x0
(4) 令 f :[π/2,3π/2]→[1,1] f(x) = sinx
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某些重要函数
定义8.7 (1)设 f:A→B, 如果存在c∈B使得对所有的 x∈A都有 f(x)=c,
射函数, 但不一定是从B到A的双射函数 (3) 对于双射函数 f:A→B, f 1:B→A是从B到A的双射函数.
定理8.4 设 f:A→B是双射的, 则f 1:B→A也是双射的. 证明思路： 先证明 f 1:B→A，即f 1是函数，且domf 1=B, ranf 1=A. 再证明f 1:B→A的双射性质.
|A|=m, |B|=n, 且m, n>0, |BA|=nm A=, 则BA=B={} A≠且B=, 则BA=A=
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实例
例1 设A={1,2,3}, B={a,b}, 求BA.
BA={ f0, f1, … , f7}, 其中 f0 = {<1,a>,<2,a>,<3,a>} f1 = {<1,a>,<2,a>,<3,b>} f2 = {<1,a>,<2,b>,<3,a>} f3 = {<1,a>,<2,b>,<3,b>} f4 = {<1,b>,<2,a>,<3,a>} f5 = {<1,b>,<2,a>,<3,b>} f6 = {<1,b>,<2,b>,<3,a>} f7 = {<1,b>,<2,b>,<3,b>}

Leave the tap running while you brush your teeth.
Leave a light on when you go out.
Drop a piece of litter and can
Activate and Share
Read and Explore
2 Pair Work Read Paragraph 1. Discuss the questions.
Read and Explore
1. What is “Just-me-ism”? “Just-me-ism” is a way of thinking that focuses on caring for just oneself and ignores the environment, animals, and the community.
Read and Explore
3 Read Paragraph 2 & 3. Complete the table.
To inspire young people to take action for the environment, animals and their community, Roots & Shoots was established. This institute was set up in the early 1990s by Dr. Jane Goodall, a scientist who’s the world’s best-known expert on wild chimpanzees. In addition to her research, she has been whole-heartedly committed to environmental protection. The whole purpose of Roots & Shoots is to educate young people, from pre-schoolers to university students, so they can help to build a future that is secure and live together in peace with nature. The organisation is called Roots & Shoots because roots move slowly under the ground to make a firm foundation, and shoots seem small and weak, but they can break open brick walls to reach the light. The roots and shoots are you, your friends and young people all around the world. Hundreds and thousands of roots and shoots can solve the problems, change the world and make it a better place to live in.