托福阅读TPO5-1原文及答案

　　答案及题目解析

　　Key:

　　1.B 2.B 3.B 4.B 5.C 6.A 7.D 8.D 9.A 10.C 11.D 12.B 13.A 14.1 2 3

　　题目解析：

　　1. According to P1, what is true of plants that can grow in serpentine soil?

　　(Factual Information Question)

　　A.They absorb micronutrients unusually well.

　　B.They require far less calcium than most plants do.

　　C.They are able to absorb nitrogen in its elemental state.

　　D.They are typically crops raised for food.

　　相关原句：

　　So-called serpentine soils, for example, are deficient in calcium, and only plants able to tolerate low levels of this mineral can survive.(Paragraph 1)

　　本题解析：

　　文中指出只有能承受低钙浓度的植物才能在蛇纹土壤中存活，因此选择B。

　　正确答案：

　　B

　　2.The word “exhibit” in the passage is closest in meaning to(Vocabulary Question)

　　A.fight off

　　B.show

　　C.cause

　　D.spread

　　相关原句：

　　Nitrogen-deficient plants exhibit many of the symptoms just described.( Paragraph 2)

　　本题解析：

　　exhibit意为“展示”，与show同义，因此选择B。

　　正确答案：

　　B

　　3.According to P2, which of the following symptoms occurs in phosphorus-deficient plants but not in plants deficient in nitrogen or iron?

　　(Factual Information Question)

　　A.Chlorosis on leaves

　　B.Change in leaf pigmentation to a dark shade of green

　　C.short, stunted appearance of stems

　　Reddish pigmentation on the leaves or stem

　　相关原句：

　　Phosphorus-deficient plants are often stunted, with leaves turning a characteristic dark green, often with the accumulation of anthocyanin.( Paragraph 2)

　　本题解析：

　　文中指出，叶子显示出特殊深绿色(with leaves turning a characteristic dark green)是缺磷才有的独特症状，因此选择B。

　　正确答案：

　　B

　　4.According to P2, a symptom of iron deficiency is the presence in young leaves of(Factual Information Question)

　　A.deep red discoloration between the veins.

　　B.white or yellow tissue between the veins.

　　C.dead spots between the veins.

　　D.characteristic dark green veins.

　　相关原句：

　　chlorosis (loss of chlorophyll resulting in yellow or white leaf issue);( Paragraph 2)

　　Iron deficiency is characterized by chlorosis between veins in young leaves. ( Paragraph 2)

　　本题解析：

　　文中指出缺铁植物的新生叶子纹路间会出现萎黄现象，即黄白叶组织(yellow or white leaf issue)的出现。因此选择B。

　　正确答案：

　　B

　　5.The word “facilitates” in the passage is closest in meaning to(Vocabulary Question)

　　A.slows down

　　B.affects

　　C.makes easier

　　D.focuses on

　　相关原句：

　　Hydroponics has applications beyond basic research, since it facilitates the growing of greenhouse vegetables during winter.( Paragraph 3)

　　本题解析：

　　facilitate意为“使…便利”，与make easier吻合，因此选择C。

　　正确答案：

　　C

　　6.According to P3, what is the advantage of hydroponics for research on nutrient deficiencies in plants?

　　(Factual Information Question)

　　A.It allows researchers to control what nutrients a plant receives.

　　B.It allows researches to observe the growth of a large number of plants simultaneously.

　　C.It is possible to directly observe the roots of plants.

　　D.It is unnecessary to keep misting plants with nutrient solutions.

　　相关原句：

　　This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the plants. ( Paragraph 3)

　　本题解析：

　　文中指出水栽法使得科学家可以控制溶液中的营养成分，从而观察其对植物的影响。因此选择A。

　　正确答案：

　　A

　　7.The word “suspended” in the passage is closest in meaning to(Vocabulary Question)

　　A.grown

　　B.protected

　　C.spread out

　　D.hung

　　相关原句：

　　Acroponics, a technique in which plants are suspended and the roots misted with a nutrient solution, is another method for growing plants without soil. ( Paragraph 3)

　　本题解析：

　　suspend意为“悬起，挂起”，与hang同义，因此选择D。

　　正确答案：

　　D

　　8.Why does the author mention herbs, shrubs, and trees?

　　(Rhetorical Purpose Question)

　　A.To provide examples of plant types that cannot tolerate high levels of harmful minerals.

　　B.To show why so many plants are hyperaccumulators.

　　C.To help explain why hyperaccumulators can be found in so many different places.

　　D.To emphasize that hyperaccumulators occur in a wide range of plant types.

　　相关原句：

　　Hyperaccumulators run the entire range of the plant world.

　　They may be herbs, shrubs, or trees.( Paragraph 5)

　　本题解析：

　　前句中先指出超聚植物遍布植物世界各个物种形态，接着列举“草，灌木和树木”是为了对这一观点进行强调和证明。因此选择D。

　　正确答案：

　　D

　　9.The word “afford” in the passage is closest in meaning to(Vocabulary Question)

　　A.offer

　　B.prevent

　　C.increase

　　D.remove

　　相关原句：

　　Many are found in tropical and subtropical areas of the metals may afford some protection against plant-eating insects and microbial pathogens. ( Paragraph 5)

　　本题解析：

　　offord此处意为“给予，提供”，与offer同义，因此选择A。

　　正确答案：

　　A

　　10.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage?

　　(Sentence Simplification Question)

　　A.Before considering phytoremediation, hyperaccumulating species of plants local to the target area must be identified.

　　B.The investigation begins with an evaluation of toxic sites in the target area to determine the extent of contamination.

　　C.The first step in phytoremediation is the planting of hyperaccumulating plants in the area to be cleaned up.

　　D.Mines and irrigation ponds can be kept from becoming contaminated by planting hyperaccumulating species in targeted areas.

　　相关原句：

　　This scenario begins with the planting of hyperaccumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by runoff.( Paragraph 6，highlighted sentence)

　　本题解析：

　　阴影句指出植物修复术的第一步就是在目标污染区种植超聚植物，因此选择C。

　　正确答案：

　　C

　　11.It can be inferred from P6 that compared with standard practices for remediation of contaminated soils, phytoremediation(Inference Question)

　　A.does not allow for the use of the removed minerals for industrial purposes.

　　B.can be faster to implement

　　C.is equally friendly to the environment

　　D.is less suitable for soils that need to be used within a short period of time.

　　相关原句：

　　After several years of cultivation and harvest, the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated soils. (Paragraph 6)

　　本题解析：

　　文中指出利用植物修复术通常需要几年的时间(After several years of cultivation and harvest)，这对于那些需要迅速清除重金属的土壤就不太适合了。因此选择D。

　　正确答案：

　　D

　　12.Why does the author mention Indian mustard?

　　(Rhetorical Purpose Question)

　　A.To warn about possible risks involved in phytoremediation

　　B.To help illustrate the potential of phytoremediation

　　C.To show that hyperaccumulating plants grow in many regions of the world

　　D.To explain how zinc contamination can be reduced.

　　相关原句：

　　For examples, in field trials, the plant alpine pennycress removed zinc and cadmium from soils near a zinc smelter, and Indian mustard, native to Pakistan and India, has been effective in reducing levels of selenium salts by 50 percent in contaminated soils. ( Paragraph 6)

　　本题解析：

　　文中指出利用植物修复术可以降低清理成本，应用前景广泛，接着用印度芥末做例子证明这一观点。因此选择B。

　　正确答案：

　　B

　　13.Look at the four squares [■]

　　that indicate where the following sentence could be added to the passage.

　　(Insert Text Question)

　　Certain minerals are more likely to be accumulated in large quantities than others.

　　Where could the sentence best fit?

　　Scientists have known for some time that certain plants, called hyperaccumulators, can concentrate minerals at levels a hundredfold or greater than normal. ■(A) Certain minerals are more likely to be accumulated in large quantities than others.A survey of known hyperaccumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of choice. ■(B)Hyperaccumulators run the entire range of the plant world. ■(C) They may be herbs, shrubs, or trees. ■(D)Many members of the mustard family, spurge family, legume family, and grass family are top hyperaccumulators. Many are found in tropical and subtropical areas of the metals may afford some protection against plant-eating insects and microbial pathogens.

　　本题解析：

　　插入句指出“特定矿物质非常容易被大量聚集起来”，后文中对超聚植物的调查显示多种金属被大量聚集(75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium)，证明了插入句的观点。因此选择A。

　　正确答案：

　　A