名词解释题总有机碳（Total Oxygen Carbon，简称TOC）
名词解释题
总有机碳（Total Oxygen Carbon，简称TOC）
参考解析
解析：
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相关考题：
What could result in an incorrect oxygen concentration reading on the oxygen indicator ________．A.Exposure to carbon dioxide for no more than 1 minuteB.Exposure to carbon dioxide for more than 10 minutesC.Exposure to a very low concentration of sulfur dioxide for no more than 2 minutesD.None of the above
An Essential Scientific ProcessAll life on the earth depends upon green plants. Using sunlight, theplants produce their own food. Then animals feed upon the plants. They take inthe nutrients the plants have made sted. But that’s not all.Sunlight also helps a plant produce oxygen. Some of the oxygen is used by theplant, but a plant usually produces me oxygen than it uses. The excess oxygenis necessary f animals other ganisms to live.The process of changing light into food oxygen is calledphotosynthesis. Besides light energy from the sun, plants also use water carbon dioxide. The water gets to the plant through its roots. The carbondioxide enters the leaves through tiny openings called stomata. The carbondioxide travels to chloplasts, special cells in the bodies of green plants.This is photosynthesis takes place. Chloplasts contain the chlophyllsthat give plants their green col. The chlophylls are the molecules thattrap light energy. The trapped light energy changes water carbon dioxide toproduce oxygen a simple sugar called glucose.Carbon dioxide oxygen move into out of the stomata. Watervap also moves out of the stomata. Me than 90 percent of water a planttakes in through its roots escapes through the stomata. During the daytime, thestomata of most plants are open. This allows carbon dioxide to enter the leavesf photosynthesis. As night falls, carbon dioxide is not needed. The stomataof most plants close. Water loss stops.If photosynthesis ceased, there would be little food other ganicmatter on the earth. Most ganisms would disappear. The earth’s atmospherewould no longer contain oxygen. Photosynthesis is essential f life on ourplanet. 词汇：nutrient n.营养物 ganism n.生物体，有机体carbon dioxide n.二氧化碳chloplast n.叶绿体molecule n.分子vap n.水蒸气oxygen n.氧气 photosynthesis n.光合作用chlophyll n.叶绿素glucose n.葡萄糖cease v.停止 注释：1.Then animals feed upon the plants.动物以植物为食。 练习：5.Another good title f this passage would beA.Oxygen Carbon Dioxide.B.Plants Their Roots.C.How Photosynthesis Wks.D.Why Our Earth Needs Water.
有机物污染的指标有生化需氧量（BOD5）、总生化需氧量（BODu）、化学需氧量（COD）、总需氧量（TOD）和总有机碳（TOC）等，对水质比较稳定的城市污水五者之间的数值关系为（）。A、TODTOCCODBODuBOD5B、TODCODBODuBOD5TOCC、TOCTODCOD BODuBOD5D、TODCODBOD5BODuTOC
填空题Glucose can be completely broken down into carbon dioxide and water when oxygen is present in the process called aerobic respiration.____
单选题However fast or slow the combustion rate, it is still a （） between carbon, hydrogen, sulphur and oxygen that releases heat.Aphysical deformationBstate exchangeCchemical reactionDcoalescence
单选题Carbon dioxide flooding system is used for extinguishing fires because it reduces the concentration of oxygen in the air to（）.Aflashing pointBcombustion pointCauto-ignition pointDlower explosive limit
单选题An oxygen indicator will detect （）.Athe amount of oxygen in a spaceBthe presence of harmful amounts of carbon monoxideCconcentrations of explosive gasDAll of the above
单选题Plants use the carbon, along with sunlight, for growth, and （） oxygen into the atmosphere in a process known as photosynthesis.ArelieveBrelateCreleaseDretain