C Read the magazine article about government programmes to help certain ecosystems and choose the best answer for each question.
Bring back balance
Every ecosystem has a careful balance between its plants and animals. Sometimes, the best way to keep this balance is bringing back a key animal species. This is exactly what some governments did, and the results were amazing!
In 1995, the American government brought wolves back to Yellowstone National Park. These animals were common there until the 1930s, but then hunters killed them all. Without wolves, the number of elk grew quickly, since wolves were their biggest threat. However, there were too many elk in the park, and the elk ate too many willow trees. This was terrible for beavers because they need willow trees to survive in winter. Now, with the wolves back to Yellowstone, there are fewer elk, more willow trees—and happier beavers!
A similar thing happened in Scotland. In 2009, the government introduced beavers to the country. Beavers used to live in Scotland, but hunters killed the last ones in the 16th century. Since they were introduced to Scotland, the new beavers have helped improve the environment. To build their homes, beavers bite down small trees. This allows more light to reach other plants and helps them grow. Beavers also create small ponds. These provide homes for all kinds of insects and birds. Finally, beavers often build dams to slow down the flow of river water. This can help stop flooding in the area.
Today, these two ecosystems are both doing well. The examples teach us an important lesson: sometimes, just one type of animal can change the balance of an entire ecosystem.
1 What is the main purpose (目的) of the text?
a To show how one type of animal can change an ecosystem.
b To encourage governments to protect ecosystems.
c To compare different ecosystems.
2 What happened in Yellowstone National Park in 1995?
a Hunters killed the last wolves in the park.
b The American government brought wolves back to the park.
c The elk in the park faced serious threats.
3 What was the main problem for beavers in Yellowstone National Park?
a They couldn’t find enough willow trees.
b Wolves hunted too many of them.
c The government introduced too many of them into the park.
4 Why are beavers important in Scotland?
a Because they help small trees grow.
b Because they reduce the number of insects.
c Because they improve the environment for many plants and animals.
答案：【解析】：
這是一篇英語閱讀理解題，主要考查學生對于文章主旨和細節(jié)信息的理解能力。文章主要講述了兩個生態(tài)系統(tǒng)恢復平衡的例子：一個是美國黃石國家公園通過重新引入狼來恢復生態(tài)平衡，另一個是蘇格蘭通過重新引入海貍來改善環(huán)境。題目要求根據(jù)文章內(nèi)容選擇最佳答案。
1. 第一題是主旨題，需要理解文章的整體意思，找出文章的主要目的。
2. 第二題是細節(jié)題，需要回到文章中找到1995年黃石國家公園發(fā)生的事件。
3. 第三題是細節(jié)題，需要找出黃石國家公園中海貍面臨的主要問題。
4. 第四題是細節(jié)題，需要理解海貍在蘇格蘭的重要性。
【答案】：
1. a
文章主要講述了通過重新引入一種動物來改變整個生態(tài)系統(tǒng)的平衡，因此主要目的是展示一種動物如何改變生態(tài)系統(tǒng)。
2. b
根據(jù)文章中的句子“In 1995, the American government brought wolves back to Yellowstone National Park.”可知，1995年美國政府將狼重新引入了黃石國家公園。
3. a
文章中提到，“This was terrible for beavers because they need willow trees to survive in winter.”說明海貍在黃石國家公園面臨的主要問題是找不到足夠的柳樹。
4. c
文章中提到海貍在蘇格蘭幫助改善環(huán)境，建造家園時咬下小樹，讓更多陽光照射到其他植物上，幫助它們生長，還創(chuàng)造了小池塘，為各種昆蟲和鳥類提供了家園。因此，海貍對蘇格蘭的重要性在于它們?yōu)樵S多植物和動物改善了環(huán)境。
