可汗
Questions 1-11 are bases on the following passage.
An Unusual Island
Located in the Indian Ocean, off the coast of southeastern Africa, Madagascar is the world‘s fourth-largest island. Hosting an unusually large number of species in a relatively tiny area, ①Madagascar’s biodiversity is its exceptional feature. This unusual variety is made possible in part by the island‘s geographic features. Covering less than 0.5 percent of the world‘s landmass, the island contains rainforests, mountains, and plains. ②
The vast number of species found in Madagascar stems from the fact that it has been cut off from other landmasses for 80 million years. ③As a result, the island has been an ideal setting for allopatric speciation, a process in which geographically isolated populations of the samespecies④evolves independently. Due to the diverse habitats of Madagascar, many populations have also become isolated from one another on the island itself, resulting in further speciation. Over half of the ⑤ world’s species’ of chameleons live on Madagascar. The island‘s many habitats have resulted in chameleon species that have a wide variety of sizes, diets, and camouflages. The world‘s largest and smallest species of chameleon are both found on Madagascar. The largest, Parson‘s chameleon, can be almost a meter in ⑥ length. The smallest can sit comfortably on the head of a match.
Madagascar‘s plants are just as diverse as its animals, with over 12,000 species of plants on the island found nowhere else on earth. The tallest species of palm tree on the ⑦ island, Tahina spectabilis, reaches heights of over 60 feet. Botanists and island residents alike assumed the plants were unusually tall specimens of another palm species until they were surprised by one tree‘s sudden flowering. It produced a bizarre-looking shoot that resembled a pine tree with each branch bearing hundreds of bunches of tiny white flowers. To date, only about three dozen of these ⑧ durable trees are known to exist in the wild.
⑨This palm tree was among the 600 previously unknown species discovered on Madagascar in just the first decade of the twenty-first century. The habitats that these species call home, though, are under threat. Over 23 million people live on the island, and the human population is growing. Most people on the island make their living as ⑩ a farmer, and they have to cut down forests to create fields for crops. The larger forces of global climate change are having an effect, too.
Temperatures are rising and rainfall patterns are changing. Species that have adapted to very specific, small ranges may now find them unsuitable habitats. ⑪
1
A) NO CHANGE
B) biodiversity is Madagascar‘s most exceptional feature.
C) the exceptional feature of Madagascar is biodiversity.
D) Madagascar features exceptional biodiversity.
2
At this point, the author wants to add an additional statistic that supports the paragraph‘s main point about Madagascar‘s biodiversity. Which choice best accomplishes that goal?
A) Up to 90 percent of the island‘s plant and animal species cannot be found anywhere else in the world.
B) The temperature of the Indian Ocean around Madagascar has been rising at the rate of one degree Celsius per year.
C) Madagascar‘s climate makes it ideal for coffee production, and the island exports 25.5 million kilograms of coffee annually.
D) All of the world‘s lemur species are endemic to Madagascar, but 90% of them are forecasted to go extinct within the next 50 years.
3
A) NO CHANGE
B) On the other hand,
C) In spite of this,
D) At the same time,
4
A) NO CHANGE
B) evolve
C) is evolving
D) has evolved
5
A) NO CHANGE
B) worlds‘ species
C) world‘s species
D) worlds‘ species‘
6、Which choice most effectively combines the sentences at the underlined portion?
A) length; notwithstanding, the
B) length, while the
C) length; albeit the
D) length, even though the
7
A) NO CHANGE
B) island Tahina spectabilis,
C) island, Tahina spectabilis
D) island Tahina spectabilis
8、Which choice is most consistent with the characterization of the trees throughout the paragraph?
A) NO CHANGE
B) plentiful
C) intriguing
D) beneficial
9、The writer is considering deleting the underlined sentence. Should the sentence be deleted or kept?
A) Kept, because it provides a transition between the previous paragraph and the new topic of habitat destruction.
B) Kept, because it portrays Madagascar as heavily forested, which is inconsistent with its characterization in the rest of the passage.
C) Deleted, because it provides a statistic that contradicts information presented previously in the passage.
D) Deleted, because it distracts from the paragraph‘s main idea of habitat destruction.
10
A) NO CHANGE
B) farmers,
C) farmer,
D) farming,
11、The writer wants to conclude the passage with an optimistic outlook on the problem raised in the previous sentence. Which choice best accomplishes this goal?
A) Madagascar‘s population has been growing steadily at the rate of 2.8% per year, which means forest will continue to be sacrificed to grow both subsistence crops like cassava and cash crops like coffee and vanilla.
B) Madagascar‘s gross domestic product, however, is closely linked to the prices of coffee on the commodities market, and thus should continue to increase over the next decade, providing its human population with a higher standard of living.
C) Moreover, many of Madagascar‘s unique creatures like lemurs and chameleons are frequently captured and trafficked to other countries to be sold on the illegal market for exotic pets, further reducing populations in the wild.
D) Some encouraging studies, however, show that some of Madagascar‘s unique species are altering their behavior in response to their new environments, and may still be able to thrive in their changing habitats.