III. Cloze Test（16 – 26 題，共 11 題） A. 16 – 20 題 Methane, the simplest alkane and a vital component of natural gas, is a potent greenhouse gas that significantly contributes to the anthropogenic warming of the planet. It is naturally generated via various biochemical pathways, such as anaerobic decay of organic matter, as well as anthropogenic activities, such as intensive animal husbandry and fossil fuel production. The atmospheric concentration of methane has surged by over 150% since the pre-industrial era and now constitutes 新 about 20% of the total radiative forcing caused by greenhouse gases. As reducing methane emissions has become a prime imperative for mitigating climate change impacts, several strategies ____16___, such as enhancing the efficiency of animal farming, cutting down waste generation in landfills, and trapping methane at oil and gas facilities. A new, burgeoning approach to reduce methane emissions is the exploitation of methane as a renewable energy source, particularly in the form of biogas. Biogas, a renewable, sustainable energy source, is derived by the anaerobic digestion of organic 聞 materials like animal waste, food scraps, and sewage sludge. This procedure generates a blend of methane and carbon dioxide, which can be processed to yield a purified fuel for heating, cooking, and electricity production. Biogas presents several advantages ___17___ fossil fuels, such as its ecological sustainability, minimal carbon footprint, and ability to cut down methane emissions from waste disposal practices. ___18___ its potential as a fuel source, methane can also be utilized as a feedstock for 稿 manufacturing an array of chemicals and materials. Methane, through various chemical reactions, can be converted into diverse chemicals, such as methanol, which can be used as a fuel or as a building block for producing other compounds. Methane can also be employed as a precursor for the synthesis of hydrogen, a pivotal component in numerous industrial processes. Nevertheless, several challenges and hurdles have to be surmounted to realize the full potential of methane as a fuel and feedstock. For instance, the production of biogas necessitates careful management of the anaerobic digestion process to guarantee that the methane is captured and not 專 released into the atmosphere. Moreover, the purification and transportation of biogas are complex and costly. Likewise, the conversion of methane into chemicals and materials ___19___ advanced, sophisticated technologies and procedures. In summary, methane, the simplest hydrocarbon with vast potential as a fuel and feedstock, plays a crucial role in the climate change conundrum. However, its production and utilization should be handled with extreme caution to avoid unfavorable environmental effects, including the exacerbation of climate change. By investing in cutting-edge research and development and promoting sustainable 用 practices, we can optimize the benefits of methane ___20___ mitigating its disadvantages.