托福TPO解析TPO5 Minerals and Plants

TPO 05 Paragraph1: 1. According to Paragraph1, what is true of plants that can grow in serpentine soil? · They absorb micronutrients unusually well. · They require far less calcium than most plants do. · They are able to absorb nitrogen in its elemental state. · They are typically crops raised for food. Paragraph2: 2. The word exhibit in the passage is closest in meaning to · fight off · show · cause · spread 3. According to Paragraph2, which of the following symptoms occurs in phosphorus-deficient plants but not in plants deficient in nitrogen or iron? · Chlorosis on leaves · Change in leaf pigmentation to a dark shade of green · Short, stunted appearance of stems · Reddish pigmentation on the leaves or stem 4. According to Paragraph2, a symptom of iron deficiency is the presence in young leaves of · Deep red discoloration between the veins. · White or yellow tissue between the veins. · Dead spots between the veins. · Characteristic dark green veins. Paragraph3: 5. The word facilitates in the passage is closest in meaning to · slows down · affects · makes easier · focuses on 6. According to Paragraph3, what is the advantage of hydroponics for research on nutrient deficiencies in plants? · It allows researchers to control what nutrients a plant receives. · It allows researchers to observe the growth of a large number of plants simultaneously. · It is possible to directly observe the roots of plants. · It is unnecessary to keep misting plants with nutrient solutions. 7. The word suspended in the passage is closest in meaning to · grown · protected · spread out · hung 一想到新托福，就想到咱老无。 Paragraph5: 8. Why does the author mention herbs, shrubs, and trees? · To provide examples of plant types that cannot tolerate high levels of harmful minerals. · To show why so many plants are hyper accumulators. · To help explain why hyper accumulators can be found in so many different places. · To emphasize that hyper accumulators occur in a wide range of plant types. 9. The word afford in the passage is closest in meaning to · offer · prevent · increase · remove Paragraph 6: 10. 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. · Before considering phytoremediation, hyper accumulating species of plants local to the target area must be identified. · The investigation begins with an evaluation of toxic sites in the target area to determine the extent of contamination. · The first step in phytoremediation is the planting of hyper accumulating plants in the area to be cleaned up. · Mines and irrigation ponds can be kept from becoming contaminated by planting hyper accumulating species in targeted areas. 11. It can be inferred from Paragraph6 that compared with standard practices for remediation of contaminated soils, phytoremediation · does not allow for the use of the removed minerals for industrial purposes. · can be faster to implement · is equally friendly to the environment · is less suitable for soils that need to be used within a short period of time. 12. Why does the author mention Indian mustard? · To warn about possible risks involved in phytoremediation · To help illustrate the potential of phytoremediation · To show that hyper accumulating plants grow in many regions of the world · To explain how zinc contamination can be reduced. Paragraph5: 13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Certain minerals are more likely to be accumulated in large quantities than others. Where could the sentence best fit? 14. Plants need to absorb certain minerals from the soil in adequate quantities for normal growth and development. ● ● ● Answer Choices 1. Some plants are able to accumulate extremely high levels of certain minerals and thus can be used to clean up soils contaminated with toxic levels of these minerals. 2. Though beneficial in lower levels, high levels of salts, other minerals, and heavy metals can be harmful to plants. 3. When plants do not absorb sufficient amounts of essential minerals, characteristic abnormalities result. 4. Because high concentrations of sodium chloride and other salts limit growth in most plants, much research has been done in an effort to develop salt-tolerant agricultural crops. 5. Some plants can tolerate comparatively low levels of certain minerals, but such plants are of little use for recycling nutrients back into depleted soils. 6. Mineral deficiencies in many plants can be cured by misting their roots with a nutrient solution or by transferring the plants to a soilless nutrient solution. MINERALS AND PLANTS Research has shown that certain minerals are required by plants for normal growth and development. The soil is the source of these minerals, which are absorbed by the plant with the water from the soil. Even nitrogen, which is a gas in its elemental state, in normally absorbed from the soil as nitrate ions. Some soils are notoriously deficient in micro nutrients and are therefore unable to support most plant life. So-called serpentine soils, for example, are deficient in calcium, and only plants able to tolerate low levels of this mineral can survive. In modern agriculture, mineral depletion of soils is a major concern, since harvesting crops interrupts the recycling of nutrients back to the soil. Mineral deficiencies can often be detected by specific symptoms such as chlorosis (loss of chlorophyll resulting in yellow or white leaf issue), necrosis (isolated dead patches), anthocyanin formation (development of deep red pigmentation of leaves or stem), stunted growth, and development of woody tissue in an herbaceous plant. Soils are most commonly deficient in nitrogen and phosphorus. Nitrogen-deficient plants exhibit many of the symptoms just described. Leaves develop chlorosis; stems are short and slender, and anthocyanin discoloration occurs on stems, petioles, and lower leaf surfaces. Phosphorus-deficient plants are often stunted, with leaves turning a characteristic dark green, often with the accumulation of anthocyanin. Typically, older leaves are affected first as the phosphorus is mobilized to young growing tissue. Iron deficiency is characterized by chlorosis between veins in young leaves. Much of the research on nutrient deficiencies is based on growing plants hydroponically, that is, in soilless liquid nutrient solutions. This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the plants. Hydroponics has applications beyond basic research, since it facilitates the growing of greenhouse vegetables during winter. Acroponics, a technique in which plants are suspended and the roots misted with a nutrient solution, is another method for growing plants without soil. While mineral deficiencies can limit the growth of plants, an overabundance of certain minerals can be toxic and can also limit growth. Saline soils, which have high concentrations of sodium chloride and other salts, limit plant growth, and research continues to focus on developing salt-tolerant varieties of agricultural crops. Research has focused on the toxic effects of heavy metals such as lead, cadmium, mercury, and aluminum; however, even copper and zinc, which are essential elements, can become toxic in high concentrations. Although most plants cannot survive in these soils, certain plants have the ability to tolerate high levels of these minerals. Scientists have known for some time that certain plants, called hyper accumulators, can concentrate minerals at levels a hundredfold or greater than normal. ■ A survey of known hyper accumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of choice. ■Hyper accumulators run the entire range of the plant world. ■ They may be herbs, shrubs, or trees. ■ Many members of the mustard family, spurge family, legume family, and grass family are top hyper accumulators. Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant-eating insects and microbial pathogens. Only recently have investigators considered using these plants to clean up soil and waste sites that have been contaminated by toxic levels of heavy metals – an environmentally friendly approach known as phytoremediation. This scenario begins with the planting of hyper accumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by runoff. Toxic minerals would first be absorbed by roots but later relocated to the stem and leaves. A harvest of the shoots would remove the toxic compounds off site to be burned or composted to recover the metal for industrial uses. 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. 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. TPO5 Minerals and Plants 1. 根据第一段，以下哪项关于能在蛇纹岩土上生存的植物是正确的？ （Factual Information Question） a) 它们吸收微营养的能力超常地好。 b) 相对大多植物，它们需要的钙少些。 c) 它们能吸收元素状态的氮。 d) 它们是典型的农作物。 解析：根据serpentine定位倒数第二句“So-called serpentine soils, for example, are deficient in calcium, and only plants able to tolerate low levels of this mineral can survive.”意思是：例如，所谓的蛇纹岩土就是缺钙，而且只有那种能够忍受缺钙的植物才能生存。 2. 与单词exhibit在文中意思最接近的是 （Vocabulary Question） a) Fight off （抵抗，排斥） b) Show （表现，展示） c) Cause （导致，引起） d) Spread （传播，散布） 解析：查字典：If someone or something shows a particular quality, feeling, or type of behaviour, you can say that they exhibit it. (FORMAL) He has exhibited symptoms of anxiety and overwhelming worry... = show； 释义来自科林斯高级学习词典 3. 根据第二段，以下哪个症状在缺磷的植物中出现，但不在缺氮和缺铁的植物中出现 （Factual Information Question） a) 叶子出现萎黄病 b) 叶子的色素变成深绿色 c) 出现短的，生长受抑制的茎杆 d) 叶子或茎杆出现红色素 解析：段落倒数第三句“Phosphorus-deficient plants are often stunted, with leaves turning a characteristic dark green, often with the accumulation of anthocyanin.”意思是：缺磷的植物通常生长受抑制，叶片变成特殊的深绿色，通常还带有花青素的累积。段落最后一句“Iron deficiency is characterized by chlorosis between veins in young leaves. ”意思是：缺铁的特点是幼小叶子的叶脉之间出现萎黄病。段落第三、四句“Nitrogen-deficient plants exhibit many of the symptoms just described. Leaves develop chlorosis; stems are short and slender, and anthocyanin discoloration occurs on stems, petioles, and lower leaf surfaces.”意思是：缺氮的植物显出出很多上面提到的症状。叶子有萎黄病；茎杆细短，并且在茎杆、叶柄和下叶面出现花青素颜色脱落。 通过这三句话，选项一是缺氮和缺铁时的症状；选项二是缺磷的症状；选项三事缺磷和缺氮的症状；选项四是缺磷和缺氮的症状。 4. 根据第二段，缺铁的症状是在幼小叶子上出现 （Factual Information Question） a) 叶脉之间出现深红的褪色。 b) 叶脉间白的或者黄的组织。 c) 叶脉间出现死点。 d) 叶脉出现特殊的深绿色。 解析：段落最后一句“Iron deficiency is characterized by chlorosis between veins in young leaves. ”意思是：缺铁的特点是幼小叶子的叶脉之间出现萎黄病。而段落第一句“……such as cholorosis(loss of chlorophyll resulting in yellow or white leaf issue.)”说了chlorosis症状的表现就是出现黄色或者白色的叶子组织。 5. 与单词facilitates在文中意思最接近的是 （Vocabulary Question） a) Slows down （减缓） b) Affects （影响） c) Makes easier （使得……更容易） d) Focuses on （专注于） 解析：To facilitate an action or process, especially one that you would like to happen, means to make it easier or more likely to happen. 释义来自柯林斯高级学习词典。 6. 根据第三段，水培法对研究植物营养缺陷有什么好处？ （Factual Information Question） a) 它使得研究者可以控制一个植物接受的营养。 b) 它使得研究者可以同时观察大量植物的生长。 c) 有可能直接观察植物的根。 d) 把植物一直放在营养溶剂中是没有必要的。 解析：段落第二句话“This technique allows researchers to create solutions that selectively omit certain nutrients and then observe the resulting effects on the planets.”意思是：这项技术使得研究者在配置溶剂的时候可以选择性忽略一些营养，然后观察这样对植物的影响结果。选项一是同义改写。 7. 与单词suspended在文中意思最接近的是 （Vocabulary Question） a) Grown （生长） b) Protected （保护） c) Spread out （扩散） d) Hung （悬挂） 解析：If something is suspended from a high place, it is hanging from that place. 释义来自柯林斯高级学习词典。 8. 为什么作者要提到herbs，shrubs，和trees？ （Rhetorical Purpose Question） a) 提供不能忍受高浓度有害矿物质的植物类型例子 b) 显示为什么这么多植物都是富集植物 c) 解释为什么在那么多地方都发现了富集植物 d) 强调富集植物的种类非常广泛 解析：看例子前面那句话“Hyper accumulators run the entire range of the plant world.”意思是：富集植物在整个植物世界到处都是。后面再举出有些富集植物是herbs，shrubs和trees，就是为了告诉读者富集植物种类广泛。 9. 与单词afford在文中意思最接近的是 （Vocabulary Question） a) Offer （提供） b) Prevent （防止） c) Increase （增加） d) Remove （移除） 解析：If someone or something affords you an opportunity or protection, they give it to you. 释义来自柯林斯高级学习词典。原句“Many are found ……plant-eating insects and microbial pathogens.”意思是：在世界的热带和亚热带发现很多富集植物，在那里高浓度的矿物质积累可以给予植物一些保护以防止吃植物的昆虫和微生物病菌。 10. 以下哪一项能表达出高亮句子的精华核心含义？错误选项改变重要含义或者遗漏精华信息。 This scenario begins with the planting of hyper accumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by runoff. 这个最初在目标区域（废弃的矿场或者被污水污染的灌溉池塘）种植富集植物种类。 a) 在考虑植物除污方法之前，必须要鉴别出目标区域本地的富集植物种类。 b) 调查首先对目标区域的污染低调进行估计以确认污染的程度。 c) 植物除污方法的第一步是在要清理的地方种植富集植物。 d) 通过在目标地区种植富集植物能够保持矿场和灌溉池塘不受污染。 11. 从第六段可以退出，与传统污染治理方法相比，植物除污 （Inference Question） a) 不允许把移除的矿物质用于工业目的。 b) 能更快地执行 c) 对环境同样友好 d) 不适合那些短时期就要使用的土地 解析：段落倒数第二句“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.”意思是：经过几年的种植和收割，污染点恢复的投入比标准修复污染泥土的方法（挖埋）的价格要低。 12. 为什么作者要提到“Indian mustard”？ （Rhetorical Purpose Question） a) 警告植物除污法可能带来的危险 b) 阐明植物除污的潜力 c) 显示富集植物在世界很多地区都有种植 d) 解释zinc污染是如何被减少的 解析：段落最后一句“……Indian mustard, native to Pakistan and India, has been effective in reducing levels of selenium salts by 50 percent in contaminated soils.”意思是：原生于巴基斯坦和印度的芥菜非常有效地降低了selenium salt在污染泥土中含量百分之五十。其实举这个例子就是为了说明植物除污取得了效果，那么当然这种除污方法肯定也大有潜力。 13. Look at the four squares ■that indicate where the following sentence could be added to the passage. Certain minerals are more likely to be accumulated in large quantities than others. 某些矿物质比其他矿物质更容易被大量积累。 解析：解的关键在于certain minerals。看到原文，发现第二个插入口之后谈的都是富集植物，与矿物质没关系，所以答案肯定不会是之后的插入口。然后发现第二个插入口前一句列举了很多矿物质的名字，正好是对插入句子的解释，所以答案是第一个插入口。 14. Plants need to absorb certain minerals from the soil in adequate quantities for normal growth and development. 植物需要从泥土中吸收足够量的矿物质以供正常生长和发育。 a) 一些植物能够大量吸收某些高浓度的元素，因此可以被用来清理被这些高浓度矿物质造成毒害而被污染的泥土。 b) 尽管低浓度是有益的，高浓度的盐、其他矿物质和重金属可能对植物造成伤害。 c) 当植物不能吸收足够重要的矿物质时，就会出现一些特殊异常。 d) 因为高浓度氟化钠和其他盐限制了大多数植物的生长，很多研究都致力于研发出耐盐的农业植物。 e) 一些植物能够忍受某种矿物质相对较低的浓度，但是这种植物对把营养物回收到耗尽的土壤中几乎没有帮助。 f) 很多植物缺乏矿物质可以通过将它们的根浸入营养液或者通过把植物转移到无土营养液中。 解析：选项一对，文章最后两段的主要内容； 选项二对，第四段的主要内容； 选项三对，第二段的主要内容； 选项四错，文章没有讲过农业植物的研发； 选项五错，文章没有讲过耐低浓度矿物质的植物。 选项六错，文章没有讲过这样的方法，只是在第三段提到营养液是一种好的研究方法，可以刻意排除一些矿物质。 因此，答案是：1,2,3；