Unit 5 A delicate world

Section Ⅰ Starting out & Understanding ideas

基础训练

单词拼写 根据首字母或汉语提示，用本部分所学单词的正确形式填空。

1. Thanks to the government’s intervention， the number of the patients has d to threehundred.

2. O to lack of work experience， we wasted much time and energy.

3. No one should break the e balance of nature.

4. The roof of the house c under the weight of snow after the heavy snowfall.

5. You should keep your （食欲） under control when you are hungry.

6. We tend to look on nature （保护） as some kind of favor that human beings give tothe natural world.

7. （大量的） evidence exists to support the theory.

8. The police are connecting this （事件） with last week’s attack.

选择填空 用方框中所给短语的适当形式填空。

in harmony with die out out of control in consequence participate in

1. The plane got and crashed into the sea finally.

2. This kind of creature many years ago because people failed to protect them.

3. His death was totally unexpected and， ， no plans had been made for hisreplacement.

4. Students soccer practices last month and their skills have been improvedmuch.

5. Humans can only achieve ultimate health by living nature.

课文语法填空

Macquarie Island was a beautiful place 1 its native inhabitants， including royal penguins，king penguins， and elephant seals， existed in harmony with their 2 （nature） habitat forthousands of years. However， in 1810， humans arrived on the island with rats and 3 （mouse）.They quickly took over 4 island， eating birds’ eggs and attacking baby birds. Cats werebrought to control them， but cats also liked eating birds. Meanwhile， rabbits 5 （introduce） tothe island but the exploding rabbit population provided food for cats， meaning that the number ofcats also increased 6 （rapid）. This in turn led 7 more cats hunting birds. Although all thecats were caught in 2000， rats 8 （explode） once again. Besides， the rabbits’ digging causedsome land 9 （collapse） and killed many penguins. This incident made it clear that the rat，Section Ⅰ Starting out & Understanding ideasmouse and rabbit problem needed 10 （solve） once and for all. People are taking some steps togive the island a happy ending.

1. 2. 3. 4. 5.

6. 7. 8. 9. 10.

能力提升

阅读理解

Within the beautiful scenery of Wisconsin’s Lake Chippewa lies a natural wonder that is aunique challenge for the local community. This hidden wonder is exactly a giant floating island. Theisland sometimes floats around the lake， causing a major inconvenience. Later， the local peoplecame up with a solution to this problem. Every year， local boat owners work together and push theisland away from the bridge.

Lake Chippewa was born in 1923 when a vast bog （沼泽） was changed through flooding. Soonafter that， many of the dark bogs started FdFvyZqf25k0R6N/TB+dOIlJ0iTvhXrkOJcpexc2/2A=rising to the surface and became perfect growing places forplants， with seeds carried by wind and wild birds to this floating place. Over the years， these bogshave grown plants and turned into full islands.

Although the years-old floating island does not relocate so often， when it does， it causestrouble for the community by blocking the important bridge that serves as the only passage （通道）between the lake’s east and west sides. The only solution is to push the island away. “It takes acommunity’s effort， and you must have the winds at your back to push them in，” said a resident.Moving the island also requires precision （细致）， as merely relocating it a short distance may resultin its return within days.

Some people have suggested destroying the floating island to get rid of the problem. However，the big bog in Lake Chippewa has been around for many years， and a variety of animal and plantspecies have made it their home. Therefore， local government suggests it be dealt with in a way thatwon’t do harm to wildlife， paying more attention to the fine-drawn balance between humanconvenience and environmental protection.

1. What does the underlined word “solution” in Paragraph 1 refer to？

A. Building a new bridge. B. Moving the floating island away.

C. Transforming the vast bog. D. Rebuilding the local community.

2. What does Paragraph 2 mainly tell us？

A. The formation of the floating island. B. The history of Lake Chippewa.

C. The species in Lake Chippewa. D. The impact of the wind to the island.

3. What do we learn about the relocation work from Paragraph 3？

A. It is usually finished within days. B. It can be done during windless days.

C. It requires cooperation and accuracy. D. It greatly disturbs the residents’ lives.

4. Why has the local government refused to destroy the island？

A. To save costs for local people. B. To ensure the residents’ safety.

C. To protect the wildlife on the island. D. To avoid unnecessary trouble.

阅读七选五

Trees are one of the oldest living things on earth. They play a very important role for human’sexistence. The forests and trees that are planted by humans work together with us to make the worldlook better and more beautiful. 1 Some of them are as follows.

Trees can clean soil and control soil erosion. Poisonous chemicals from various factories enterinto the soil， thus causing soil pollution. 2 Soil erosion is a serious problem that causesdegradation （退化） of soil and leads to floods. Trees and plant roots can help reduce soil erosion.Also they conserve rainwater and reduce sediment （沉积） deposits.

Trees produce oxygen. Trees play an important role in reducing the greenhouse gases. Theyconsume carbon dioxide and produce oxygen. 3 A fully grown tree produces oxygenwhich is sufficient for 10 people for a complete year. Also， they act as filters （过滤器） of the air thatwe breathe.

Trees are of commercial importance. Trees meet the need of fuel for cooking in many areasaround the world. Trees also provide timber for furniture and hundreds of household items. Woodpulp （木浆） is used for making paper in industries. 4 Some trees are even used to makemedicines.

5 They provide shelter and food for a number of animal species across the globe.Trees are especially important as they form green corridors connecting habitats with each other andwith the countryside beyond.

A. This lowers global warming.

B. Trees have beautified our planet.

C. Trees act as the habitat for wild animals.

D. In fact， trees play different roles in our environment.

E. Without trees our planet cannot be a suitable place for living.

F. Trees have the ability to store them or change them into less harmful forms.

G. Also， trees produce a number of fruits and nuts which are sold at the market.

1. 2. 3. 4. 5.