It would seem that an introduction to oxygen is unnecessary, for we deal with it and depend upon it every moment of our lives. Oxygen is to us the essential stuff of the air we breathe. We are aerobic animals who obtain energy by oxidizing foodstuffs. As such, we are wholly dependent ...
The element zirconium is used in the production of many everyday objects, energy, and even jewelry! Read this lesson to find out how zirconium is...
A. what B. which C. that D.it 相关知识点: 试题来源: 解析 3.C 【解析】考查定语从句的关系词。 句意:氧气是能助 燃的唯一气体吗?先行词为gas,指物,该空在从句中作 主语,不可省略,且先行词前有 the only 修饰,引导词只 能用 that 而不能用 which。 故选 C。 反馈 收藏 ...
Is oxygen the only gas ___ helps fire burn?A that B / C which D what 相关知识点: 试题来源: 解析 A核心短语/词汇:help sb./ sth. (to) do sth. 帮助某人/某物做某事句子译文:氧气是唯一的助燃气体吗? 本题考查定语从句。___helps fire burn 用来修饰之前的名词gas, 该从句的引导词在定...
What is NADPH used for in humans?Human Metabolism:Human metabolism is the vast array of chemical transformations which takes place in the cells of a human being. It is a highly ordered process in which a reaction is only permitted to take place if the body needs it....
What is helium used for? Helium: Helium is a chemical element that has the atomic number 2. Its symbol is 'He.' Helium was first discovered in 1868 by Jules Cesar Janssen during a solar eclipse. Answer and Explanation:1 Helium is a major component of stars, such as our Sun. In fact...
How is oxygen and carbon dioxide transported in human beings? View Solution 560 mL of carbon monoxide is mixed with 500 mL of oxygen and ignited. The chemical equation for the reaction is2CO+O2→2CO2. Calculate the volume of oxygen used and carbon dioxide formed in the above reaction. ...
原句为“Is oxygen the only gas ___ helps fire burn?”,需填入定语从句的引导词。 1. **选项A(that)**:当先行词被“the only”修饰时,通常用“that”引导定语从句(不用“which”),且从句中缺少主语,因此“that”符合语法规则。 2. **选项B(/)**:若省略关系代词,句子结构不完整(缺少主语),错误。
解析 A [解析]答案A 解析:考查定语从句.先行词 gas ,helps fire burn是定语从句,关系词在定语从句中做主语,指物,又因为先行词被the only修饰,故用that. 故选:A. 氧气是能帮助火燃烧的唯一气体. 当先行词被the only,the very,the same等修饰时,只能用that不用which....
What is the chemical formula for oxygen?Chemical Formulas:The chemical formula of a chemical compound describes the components of the compound. It lists the number of each element making up the compound. These chemical formulas are also used to make chemical calculations. ...