Unit 4 Exploring plantsPeriod oneAim:To train the students’ ability of listening and speaking.Contents:Step I Warming upQ1 What do you know about plants?Q2 Do you know what kind of plant don’t have flowers?Q3 Do you know what kind of plant have roots that live in the air?Q4 Do you know what kind of plant need animals to pollinate them?Q5 Do you know what kind of plant grow on other plants?Q6 Do you know that people buy plants that come from other countries for their gardens?Q7 Do you know that a new plant does not always grow from a seed?Step II Listen and discuss:First give some photos of the plants and then ask students answer the following question.(Page 38)Q1 How would you describe each plant?Q2 What do you think is unusual about each plant?Q3 One of the pictures shows pitcher plants and another shows “Living stones”which picture shows which plant?Now listen to Mark，Gordon and Andrea telling their class about these plants.Which students talk about which plants?Listen again and complete the table with the correct information.Period twoAim:To make students understand the text.Plant exploring in the 18th And 19th centuries.Contents:Q1 What is each paragraph about?Q2 Write down the topic of each paragraph in your own words.Q3 What happened in these years? Complete the sentences on page 33.Q4 Answer there question in groups.1) Why was there a lot of plant collecting in the 18th and 19th centuries?2) How did French missionaries come to be plant collection?3) What were some of the negative aspects of plant collecting expeditions?4) Transporting plants over long distances was a big problem, why was this?5) Why did many plants fail to reach their destinations alive? Can you thinkof any other reasons?6) What important the survival rates of plants transported long distances? 0Period threeAim:To make students master the language points in this text.Contents:Phrases:1 date back to: go back to/date fromeg: This town dates back to the Rome time2 on a large scale3 take / find/ have/ show/ find interest in.4 take the opportunity of doing sth5 go on botanical expeditions6 come into conflicts withbe in conflicts with7 accompany sb: keep sb company8 on purpose / by design / by intentionwith the purpose of9 come acrossrun into / acrossmeet with10 keep sth alive11 make a trip to s.p.12 dress as13 in…style14 result inlead tobring about15 be excited with16 have a vast variety of17 not only…but alsonot alone…but alsonot merely/ simply… but alsoA as well as BA andB as well18 distant adj. far away in space or time 远的，遥远的19 distance n. in the distancefrom the distanceat a distancekeep sb. a distance20 scale n. 1) balance for weighing磅秤2) relative size, extent, scope规模，程度on a large / small scale大/小规模on the scale of … to…按…的比例to a scale按一定比例to a scale of … to…按…的比例21 appeal to 1）恳求，恳请I am appealing on behalf of the refugees.我代表那些难民提出恳求He appeal to us for help.他恳求我们的帮助2）诉诸，诉之于Appeal to the law / a higher court3）事物引起（人的）兴趣，有吸引力，投入所为Does the film appeal to you?n. make an appeal to 吸引, 诉之于Sentence structures1.It was not until the eighteenth and nineteenth centuries that the explorationof the botanical world began on a large scale.2.Not only did Fortune introduce over 120 species of plants to western gardensbut he also shipped 20000 tea plants from…Period FourAim:To make students understand the textFlowers and their animal pollinatorsContents:I. Questions:1)What is the text about?2)What do the pictures show you?3)What is the chart about?4)What is the advantage for animal of visiting flowers?5)Who do some plants need animals?6)How does an animal pollinate a flower?7)What is nectar?8)What kinds of animals are most flowers pollinated by?II. Language points1.over time 随着时间的推移over the weekend 整个周末里over these years 在这些年里2.reward sb with sth用…回报某人3.attach… to依附于…上4.pass on to把…往下传5.adapt to 使…适应The spokesman adapts his speech to suit the interests of his audience.He has adapted to the climate here.6.describe … as 把…描述成7.guide sb to s.p.把…领到…nd on 登陆9.provide sb. with sth向…提供provide sth for sb.provide for 养活，规定III. Difficult sentences1)Pollen becomes attached to the animals during its visit to a flower and is thenpassed on to another plant’s blossom on its next visit.动物接触一朵花后,花粉就附着在它身上,动物接触下一种植物的花时就把这些花粉传到花朵上.2)Through evolution, most flowers have become adapted to attract specific typesof pollinators.通过进化,大部分花朵变得适于吸引特殊种类的花粉传播者.四、排序不等式（一）概念【9】：设有两组实数n a a a ，，，⋅⋅⋅21 （1） n b b b ，，，⋅⋅⋅21 （2） 满足n a a a ≤⋅⋅⋅≤≤21 （3）n b b b ≤⋅⋅⋅≤≤21 （4）另设n c c c ,21⋅⋅⋅，， （5） 是实数组（2）的一个排列，记逆序积和1121b a b a b a S n n n +++=-乱序积和n n c a c a c a S +++=2211'似序积和n n b a b a b a S +⋅⋅⋅++=2211''那么'''S S S ≤≤且等式成立当且仅当n a a a =⋅⋅⋅==21或者n b b b =⋅⋅⋅==21证明【9】：1，预备知识引理1（Abel 变换） 设（1）（2）为任意两组有序的实数组，令,010∑===ki i k b B B ， 那么k n k n k k k n n k k B a a B a b a ∑∑=-=---=1111)(事实上：=-=∑∑==-n k nk k k k k k B B a b a 111)(112111)()(B a B B a B B a n n n n n n +⋅⋅⋅+-+------⋅⋅⋅-----=-------)()(2221111n n n n n n n n n n B a B a B a B a B a 112)(B a a -∑-=---=111)(n k k k k n n B a a B a引理2 设实数组（2）满足（4）式，实数组（5）是实数组（2）的任意一个排列，那么显然有∑∑∑=+-==≤≤k i i n k i i k i i b c b 1111 引理3 设实数组（2）满足（4），那么。