（2）发展：春秋时期的钢是块炼钢。南北朝时发明了更先进的灌钢法。即利用生铁碳高、熟铁碳低的特点，将熔化的生铁液灌到熟铁上以改变碳分，生产出硬度高、性能好的钢。铁器的广泛使用，特别是把钢应用到农具和手工业工具制作上，大大推动了生产力的发展。（3）燃料：冶炼金属需要原料。早在汉代开始用...
二、阅读部分: 阅读部分是雅思考试的第二项测试,它主要考察考生对英语阅读的理解和分析能力。下面是一道常见的阅读题: 题目: Which of the following statements about greenhouse gases is true?相关知识点: 试题来源: 解析 解析: 这道题要求选出正确的有关温室气体的陈述。在文章中,首先提到温室气体的定义:“...
Which of the following is a set of green house gases ? View Solution Which of the following are green house gases ? (a)CO2(b)O2(c)O3(d) CFC (e)H2O View Solution Which is a green house gas ? View Solution Which of the following is not a part of green chemistry?
百度试题 结果1 题目Which two of the below greenhouse gases have the longest residence time? A. Carbon Dioxide B. Perfluorocarbons C. Sulphur Hexafluoride D. Nitrous Oxide E. Methane 相关知识点: 试题来源: 解析 BC 反馈 收藏
The term 'greenhouse gases' includes several gases. Which of the following is NOT a greenhouse gas? A. oxygen B. carbon dioxide C. methane D. nitrous oxide 相关知识点: 试题来源: 解析 A。“greenhouse gases(温室气体)”主要包括二氧化碳、甲烷、氧化亚氮等,氧气不是温室气体。
The greenhouse effect is mainly caused by certain gases in the atmosphere. Which of the following is one of the main greenhouse gases? A. Oxygen B. Nitrogen C. Carbon dioxide D. Hydrogen 相关知识点: 试题来源: 解析 C。解析:温室效应主要是由大气中的某些气体引起的。氧气是人类呼吸所必需的...
A. Global warming can’t alter the saltiness of the sea. B. The Day After Tomorrow is a true film. C. Greenhouse gases are the result of changing salinity. D. Global warming affects the sea water salinity. 相关知识点: 试题来源: 解析...
Which of the following is a green house gas View Solution Which of the following substances is a (are) greenhouse gas(es) ? View Solution Doubtnut is No.1 Study App and Learning App with Instant Video Solutions for NCERT Class 6, Class 7, Class 8, Class 9, Class 10, Class 11 and ...
Global warming is a reality.There’s no question that greenhouse gases are there and that they are going to increase.They have a residence(存在) time of about 300 years in the atmosphere,so it’s going to take a long time.We really have to do two things.One is that we have to live...
Which of the following has Britain NOT done to decrease emissions of greenhouse gases A.Introduced catalytic converters on cars.B.Encouraged use of low sulphur and lead-free petrol.C.Replaced coal and oil with gas in power generation.D.Closed down some heavy industry factories. 相关知识点: ...