托福培训
托福考试动态
2018-04-20 13:22
来源:
作者:
Paragraph 2: Spores light enough to float on the breezes were carried thousands of miles from more ancient lands and deposited at random across the bare mountain flanks. A few of these spores found a toehold on the dark, forbidding rocks and grew and began to work their transformation upon the land. Lichens were probably the first successful flora. These are not single individual plants; each one is a symbiotic combination of an alga and a fungus. The algae capture the Sun's energy by photosynthesis and store it in organic molecules. The fungi absorb moisture and mineral salts from the rocks, passing these on in waste products that nourish algae. It is significant that the earliest living things that built communities on these islands are examples of symbiosis, a phenomenon that depends upon the close cooperation of two or more forms of life and a principle that is very important in island communities.
1. The phrase at random in the passage is closest in meaning to
○finally
○over a long period of time
○successfully
○without a definite pattern
2. It can be inferred from paragraph 2 that the fungi in lichens benefit from their symbiotic relationship with algae in what way?
○The algae help the fungi meet some of their energy needs.
○The algae protect the fungi from the Sun's radiation.
○The algae provide the fungi with greater space for absorbing water.
○The fungi produce less waste in the presence of algae.
3. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
○Some of the earliest important examples of symbiosis-the close cooperation of two or more living things-occur in island communities.
○Symbiosis-the close cooperation of pairs or small groups of living organisms-is especially important in these island environments.
○The first organisms on these islands worked together closely in a relationship known as symbiosis, which is particularly important on islands.
○It is significant to note that organisms in the beginning stages of the development of island life cannot survive without close cooperation.
Paragraph 3: Lichens helped to speed the decomposition of the hard rock surfaces, preparing a soft bed of soil that was abundantly supplied with minerals that had been carried in the molten rock from the bowels of Earth. Now, other forms of life could take hold: ferns and mosses (two of the most ancient types of land plants) that flourish even in rock crevices. These plants propagate by producing spores-tiny fertilized cells that contain all the instructions for making a new plant-but the spores are unprotected by any outer coating and carry no supply of nutrient. Vast numbers of them fall on the ground beneath the mother plants. Sometimes they are carried farther afield by water or by wind. But only those few spores that settle down in very favorable locations can start new life; the vast majority fall on barren ground. By force of sheer numbers, however, the mosses and ferns reached Hawaii, survived, and multiplied. Some species developed great size, becoming tree ferns that even now grow in the Hawaiian forests.
4. The word abundantly in the passage is closest in meaning to
○occasionally
○plentifully
○usefully
○fortunately
5. The word propagate in the passage is closest in meaning to
○multiply
○emerge
○live
○evolve
6. According to paragraph 3, what was the relationship between lichens and ferns in the development of plant life on Hawaii?
○Ferns were able to grow because lichens created suitable soil.
○The decomposition of ferns produced minerals that were used by lichens.
○Lichens and ferns competed to grow in the same rocky environments.
○Lichens and ferns were typically found together in volcanic areas.
Paragraph 4 Many millions of years after ferns evolved (but long before the Hawaiian Island were born from the sea), another kind of flora evolved on Earth: the seed-bearing plants. This was a wonderful biological invention. The seed has an outer coating that surrounds the genetic material of the new plant, and inside this covering is a concentrated supply of nutrients. Thus, the speed's chances of survival are greatly enhanced over those of the naked spore. One type of seed-bearing plant, the angiosperm, includes all forms of blooming vegetation. In the angiosperm the seeds are wrapped in an additional layer of covering. Some of these coats are hard-like the shell of a nut-for extra protection. Some are soft and tempting, like a peach or a cherry. In some angiosperm the seeds are equipped with gossamer wings, like the dandelion and milkweed seeds. These new characteristics offered better ways for the seeds to move to new habitats. They could travel through the air, float in water, and lie dormant for many months.
7. The word This in the passage refers to
○the spread of ferns and mosses in Hawaii
○the creation of the Hawaiian Islands
○the evolution of ferns
○the development of plants that produce seeds
8. According to paragraph 4, why do seeds have a greater chance of survival than spores do? To receive credit, you must select TWO answer choices.
○Seeds need less water to grow into a mature plant than spores do.
○Seeds do not need to rely on outside sources of nutrients.
○Seeds are better protected from environmental dangers than spores are.
○Seeds are heavier than spores and are therefore more likely to take root and grow.
9. Why does the author mention a nut, a peach, and a cherry?
○To indicate that some seeds are less likely to survive than others
○To point out that many angiosperms can be eaten
○To provide examples of blooming plants
○To illustrate the variety of coverings among angiosperm seeds
10. The word dormant in the passage is closest in meaning to
○hidden
○inactive
○underground
○preserved
新东方留学院校库,留学选校有门道
A BETTER YOU,A BIGGER WORLD!
版权及免责声明
①凡本网注明"稿件来源:新东方"的所有文字、图片和音视频稿件,版权均属新东方教育科技集团(含本网和新东方网) 所有,任何媒体、网站或个人未经本网协议授权不得转载、链接、转贴或以其他任何方式复制、发表。已经本网协议授权的媒体、网站,在下载使用时必须注明"稿件来源:新东方",违者本网将依法追究法律责任。
② 本网未注明"稿件来源:新东方"的文/图等稿件均为转载稿,本网转载仅基于传递更多信息之目的,并不意味着赞同转载稿的观点或证实其内容的真实性。如其他媒体、网站或个人从本网下载使用,必须保留本网注明的"稿件来源",并自负版权等法律责任。如擅自篡改为"稿件来源:新东方",本网将依法追究法律责任。
③ 如本网转载稿涉及版权等问题,请作者见稿后在两周内速来电与新东方网联系,电话:010-60908555。
托福培训
托福考试动态