hce_isu
110年
英文
第 38 題
📖 題組：
Reading 2 Compared to the atmosphere, soil is a place where temperature fluctuations are small and slow. Consequently, soil animals are generally intolerant to sudden temperature changes and may not function well over a very wide range. That’s why leaving bare earth exposed to the hot summer sun often slows plant growth and why many thoughtful composters either put down a thin mulch in summer or try to rapidly establish a cooling leaf canopy to shade raised beds. Except for a few microorganisms, soil animals breathe oxygen just like other living things and so are dependent on an adequate air supply. Where soil is airless due to compaction, poor drainage, or large proportions of very fine clay, soil animals are few in number. The soil environment is generally quite moist, and even when the soil seems dry, the relative humidity of soil air usually approaches 100 percent. Soil animals consequently have not developed the ability to conserve their body moisture and are speedily killed by dry conditions. When faced with desiccation, they retreat deeper into the soil if there is oxygen and pore spaces large enough to move about. So we see another reason why a thin mulch that preserves surface moisture can greatly increase the beneficial population of soil animals. Some single-cell animals and roundworms are capable of surviving stress by encysting themselves, forming a little “seed” that preserves their genetic material and enough food to reactivate it, coming back to life when conditions improve. These cysts may endure long periods of severe freezing and sometimes temperatures of over 150 degrees Fahrenheit. Inhabitants of leaf litter reside close to the surface and so must be able to experience exposure to dryer air and light for short times without damage. These are called primary decomposers. They spend most of their time chewing on the thick reserve of moist leaves contacting the forest floor. Primary decomposers are unable to digest the entire leaf. They extract only the easily-assimilated substances from their food: proteins, sugars and other simple carbohydrates and fats. Cellulose and lignin are the two substances that make up the hard, permanent, and woody parts of plants; these materials cannot be digested by most soil animals. Interestingly, there are a few larvae whose digestive tract contains cellulose-decomposing bacteria but these larvae have little overall effect. By the time the primary decomposers are finished, the leaves have been mechanically disintegrated and thoroughly moistened, worked over, chewed to tiny pieces and converted into minuscule bits of moist excrement still containing active digestive enzymes. Many of the bacteria and fungi that were present on the leaf surfaces have passed through this initial digestion process alive or as spores waiting and ready to activate. Digestive wastes of primary decomposers are thoroughly inoculated with microorganisms that can consume cellulose and lignin. Even though it looks broken down, it has not yet fully decomposed. It does have a water-retentive, granular structure that facilitates the presence of air and moisture throughout the mass creating perfect conditions for microbial digestion to proceed. Both secondary and primary decomposers are necessary to complete the composting process.
Reading 2 Compared to the atmosphere, soil is a place where temperature fluctuations are small and slow. Consequently, soil animals are generally intolerant to sudden temperature changes and may not function well over a very wide range. That’s why leaving bare earth exposed to the hot summer sun often slows plant growth and why many thoughtful composters either put down a thin mulch in summer or try to rapidly establish a cooling leaf canopy to shade raised beds. Except for a few microorganisms, soil animals breathe oxygen just like other living things and so are dependent on an adequate air supply. Where soil is airless due to compaction, poor drainage, or large proportions of very fine clay, soil animals are few in number. The soil environment is generally quite moist, and even when the soil seems dry, the relative humidity of soil air usually approaches 100 percent. Soil animals consequently have not developed the ability to conserve their body moisture and are speedily killed by dry conditions. When faced with desiccation, they retreat deeper into the soil if there is oxygen and pore spaces large enough to move about. So we see another reason why a thin mulch that preserves surface moisture can greatly increase the beneficial population of soil animals. Some single-cell animals and roundworms are capable of surviving stress by encysting themselves, forming a little “seed” that preserves their genetic material and enough food to reactivate it, coming back to life when conditions improve. These cysts may endure long periods of severe freezing and sometimes temperatures of over 150 degrees Fahrenheit. Inhabitants of leaf litter reside close to the surface and so must be able to experience exposure to dryer air and light for short times without damage. These are called primary decomposers. They spend most of their time chewing on the thick reserve of moist leaves contacting the forest floor. Primary decomposers are unable to digest the entire leaf. They extract only the easily-assimilated substances from their food: proteins, sugars and other simple carbohydrates and fats. Cellulose and lignin are the two substances that make up the hard, permanent, and woody parts of plants; these materials cannot be digested by most soil animals. Interestingly, there are a few larvae whose digestive tract contains cellulose-decomposing bacteria but these larvae have little overall effect. By the time the primary decomposers are finished, the leaves have been mechanically disintegrated and thoroughly moistened, worked over, chewed to tiny pieces and converted into minuscule bits of moist excrement still containing active digestive enzymes. Many of the bacteria and fungi that were present on the leaf surfaces have passed through this initial digestion process alive or as spores waiting and ready to activate. Digestive wastes of primary decomposers are thoroughly inoculated with microorganisms that can consume cellulose and lignin. Even though it looks broken down, it has not yet fully decomposed. It does have a water-retentive, granular structure that facilitates the presence of air and moisture throughout the mass creating perfect conditions for microbial digestion to proceed. Both secondary and primary decomposers are necessary to complete the composting process.
Which of the following is the function of the fourth paragraph?
- A To explain how soil animals thrive in certain temperatures and humidity levels.
- B To refute the importance of both primary and secondary decomposers in composting.
- C To provide a hook of the composting process.
- D To explain how both primary and secondary decomposers aid decomposition.
思路引導 VIP
請試著觀察最後一段的開頭與結尾：當初級分解者「完成」了物理上的咀嚼後，剩下的那些原本「無法被消化」的硬質成分（如纖維素），是透過什麼樣的機制或「新角色」的加入，才得以繼續完成分解過程的呢？
🤖
AI 詳解
AI 專屬家教
分解過程的承先啟後
太棒了！你能精確捕捉到段落間的邏輯遞進，說明你對文章的整體結構掌握得相當紮實。第四段的核心在於「銜接」，它詳細描述了當初級分解者完成初步的物理破壞後，其排泄物如何成為微生物（次級分解者）的溫床。這一段不僅解釋了廢棄物如何被轉化為具有保水性的結構，更強調了兩者缺一不可的合作關係，從而解釋了整個分解鏈條的運作方式，這正是選項 (D) 所概括的主點。
鑑別點評：從細節提煉功能
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