1、外研版英语 选择性必修第二册Unit 5 A delicate world Period 2 Using languages a.No visitors would think it surprising that the island is a UNESCO World Heritage Site.b.No visitors would think that island being a UNESCO World Heritage Site is surprising.1.What does“it”refer to in sentence(a)?In sentences(a)refers t
2、o“that the island is a UNESCO World Heritage Site”c.Experts felt it necessary to come up with a plan to remove all the rabbits from the island.d.Experts felt to come up with a plan to remove all the rabbits from the island was necessary.2.What does“it”refer to in sentence(c)?In sentences (c)refers t
3、o“to come up with a plan to remove all the rabbits from the island”Compare the sentences in each group3.What is the difference between the sentences in each group?In the 1st group,the object of the 1st sentence is replaced by“it”,whileIn the 2nt sentence,the object clause is in the position of the o
4、bject.In the 2nd group,the object of the 1st sentence is replaced by“it”,whilein the 2nd sentence,the infintive is in the position of the object.1.This incident made it clear that the rat,mouse and rabbit problem needed solving once and for all.2.but we humans owe it to the island to give it a happy
5、 ending.Notes:To balance sentence structure,the auther used an empty object to replaces too long infinitive structures or object clause.Rewrite the underlined parts using it as an empty object.1.Due to its cute appearance,many people think keeping this turtle as a pet is a good idea.2.and some owner
6、s believe to release them into the wild is no big issue.Due to its cute appearance,many people think it a good idea to keep this turtle as a pet is and some owners believe it no big issue to release them into the wild.3.These days,people have found to release these turtles into the wild is a threat
7、to other species.4.Experts consider owners keeping their pets in an enclosed area importantThese days,people have found it a threat to other species to release these turtles into the wild.Experts consider owers it important for owners to keep their pets in an enclosed area.Describe the changes happe
8、ning to the parks,using it as an empty object.the Saihanba National Forest Parknouns/adjectivesto do/that-clausebreakthroughgrowimpossibleinvestigatelikelyplant treesunrealistictransform.eg.I think it a breakthrough to transform a desert into a forest.Possible answers:1.I believe it likely that more
9、 volunteers will help plant more trees around the park.2.I find it impossible to investigate all the living species in the park at present.3.I feel it unrealistic for the local people to grow rice and wheat for gian industry.Before listeningFood chains andenergy exchangeDecomposers break down dead a
10、nimial and vegetable matter into nutrients.The dissolved chemicals are then released back into the food chain,to be used by producers.1.What does the diagram show?2.What are the relationships between the living things?Everything in the world is related to each other.Creatures in nature depend upon e
11、ach other and coexsit with each other.Listen to the conversation and choose the true statements.1.Bees are very important to our food supply because they provide honey.2.The bee population is declining.3.Without bees,humans would die out.4.All human crops depend on bees for pollination.5.If bees bec
12、ome extinct,other insects could pollinate enough crops.6.Humans are responsible for the decline in the bee population.Your answer:_IN a woodland ecosytem,trees and other plants are producers.They 1._ water,and take in nutrients from the soil and energy from the sun.Insects are an example of a primar
13、y consumer.They 2._the producers to provide food for them,and are 3._ by secondary consumers:small mammals and birds.They 4._ the primary comsumers.worms,fungi and bacteria are decomposers.They 5._ animals waste and the remains of the living things.The chemicals these decomposers 6 _ fertilise the s
14、oil and give the plants the nutrients they need to grow.absorbrely on preyed on feed onbreak down releaseLearn how to express your doubt or respond to doubt.1You must be kidding!2I dont believe it!3Its a fact!4Dont forget that.5Are you sure about.?6Check it out for yourself.7According to statistics.
15、Expressing doubtResponding to doubt1,2,5 3,4,6,7Work in pairs.Talk about what would happen to the ecosytem if another species died out.Reference:Every organism plays an irreplaceable role in the ecosystem,even the mouse or a kind of pests.The extinction of one organism may lead to the lack of food f
16、or others,while some organisms may lose their natural enemies and have uncontrolled numbers,thus affecting the whole ecosystem and the whole biosphere.1._2._3._4._5._6._7._1.Recent years have seen more and more pet sliders escaping or being released from homes.句式分析 本句主谓部分采用“时间+have seen”,其中see意为“见证经
17、历”，注意主谓人称数的一致性；see sb/sth doing 表示看见正在进行，see sb/sth being done表示看见正在被执行的动作。尝试翻译 近年来，越来越多的宠物龟逃出家门或被放生。2.In just one journey to collect pollen and nectar,one single honey bee pollinate as many as 50 to 100 flowers.句式分析 句中“to collect pollen and nectar”为不定式短语作后置定语，修饰其前面的名词；as many as+数量+名词 表示“多达.”,强调数量之
18、多。尝试翻译 在一次采集花粉和花蜜的旅程中，一只蜜蜂授粉多达50到100朵花。1.be native to 7.check out 2.feed on 8.rely on/upon 3.prey on 9.absorb.from.4.break down 10.a combination of 5.take in 11.release.into.6.in existence 12.transform.into.1.Review the vocabulary and the language ponits of the text.2.Listen to the material Page 7 once more and get more information.3.Write a short passage about impacts of species extinction.