课件19张PPT。人教课标
高二 必修 5 Unit 1Listening
on Page 41Unit 1 Great scientists Robert Briggs is very interested
in biology and especially in the study
of plants. Today he is telling his friend
Zhang Wei some exciting news.
Before you listen to the tape
discuss with your partner how you
would find out the name of a flower. New words in the listening passage:
species 种类
parrot 鹦鹉
blackbird 乌鸦 Now listen to the tape.
1. Which of the following statements describes what this listening passage is about? Give your reasons.A. This is about a man who wants to name
a flower.
B. This is about a man who finds a flower
and wants to own it.
C. This is about a man who finds a flower
and wants to know if it is a new species
of flower. It does not give enough information.B is inaccurate. Listen to the tape again and complete the following passage.
To find the name of an unknown flower first you should ask your _______ teacher to help you. He /She will look in a special _____ written by Carl Linnaeus. He lived in _______ from ____ to _____. biologybookSweden17071778He was very important because he solved a _______ problem for biology. seriousListen to the tape for the third time and answer these questions. 1. If Robert Briggs finds the flower in the book, what does that mean?
It means that his flower has already been identified and has a name.
2. How would he know if his lily is a new species?
He would know by checking his lily against other lilies in the specialist book. If his lily is different it will be a new species. 3. Why do plants all have two names?
All plants have two names just like people. The first is the group of flowers they belong to and is like the family name. The second is the kind of flower within that group and is like a given/personal name. 4. What was the serious problem for biology that Linnaeus solved?
Before Linnaeus there was no way of finding out whether a plant was new or not. This caused problems because different scientists claimed that they had found and named flowers first. After he organized his system it was easy to discover whether a plant was new or not and so who had the right to name it.Listening Taskon Page 44Make a list of all the great mathematicians that you know of or have learned about. What do you know of their achievements?DiscussionLeonhard Euler (1707-1783) Nationality Swiss
Fields Mathematician and Physicist pure (纯的) symbol (符号)
Л (圆周率) sine (正弦)
cosine (余弦) topology (拓扑学)
angle (角) diagram (图表)Read the words below and learn to pronounce them correctly. pure (纯的) symbol (符号)
Л (圆周率) sine (正弦)
cosine (余弦) topology (拓扑学)
angle (角) diagram (图表)Listen to Part 1 and tick the words below that Euler introduced into mathematics.Listen to Part 2 and fill in the chart below.topology introduced many new symbols into maths
wrote more books than anyone before or since
discovered a new branch of mathematicsWhat was the problem of the city of
Konigsberg? It had a river running through it. The centre of Konigsberg is an island and as it passes the island the river breaks into two parts. Seven bridges were built so that the people of the city could get from one part to another. The people wondered if you could walk around the city so that you would cross each bridge only once.课件14张PPT。人教课标
高二 必修 5 Unit 1Reading taskon Page 44Unit 1 Great scientistsWhat’s Euler’s puzzle?
Koningsberg is an island and there is a river breaking it into two parts. “Seven Bridges of Konigsberg” and the famous “Euler path”.People wondered if they could walk around the city by crossing the seven bridges without going over any of them twice or going back on himself, but Euler found he couldn’t cross all the seven ones. This is Euler’s puzzle. The first stage in his research is to find the problem that he could cross six of the bridges without going over any of them twice or going back on himself, but he couldn’t cross all seven. How did Euler prepare for his research?The second stage is to think of a
method: He drew a map and used
dots and lines to simplify his analysis.
Trying and observing over and over
again, he found a general rule. It is topology. Euler’s theory is called “The Euler path”, which is expressed like this: If a figure has more than two odd points, you cannot go over it without lifting your pencil from the page or going over a line twice. What are the theories?So the general rule that Euler found is the even points and the odd points.Look at the following pictures:Conclusion
Euler’s theory (一笔画)
可以一笔画只有两种情况：
1. 没有奇数顶点。
2. 只有两个奇数顶点。
