A. Silicon atoms. B. Carbon atoms. C. Oxygen atoms. D. Hydrogen atoms. 相关知识点: 试题来源: 解析 B。解析:文章中明确提到“Graphene is an extremely thin and strong material. It is made up of a single layer of carbon atoms arranged in a hexagonal lattice.”,石墨烯是由一层碳原子组成...
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语从句中做主语,不能省略,先行词有only 修饰时不能用which; what 不能引导定语从句,故选项A符合题意。反馈...
第1题 The two elements water is made are oxygen and hydrogen.A、that B、which C、of which D、with which 第2题 The crime was discovered till 48 hours later,gave the criminal plenty of time to get away.A、which B、that C、so D、what 第3题 The International Studies University,in 1951...
It is vital that we do something to save the earth. First of all, what are the___to our environment? The writers ask us to ‘imagine the earth inside a kind of greenhouse with the atmosphere around it ___like the glass, letting sunlight in while keeping much ...
Oxygen is a vital element for life. 11 Essence An extract or concentrate obtained from a plant or other matter used for flavoring. Vanilla essence is commonly used in baking. 7 Element A group in a scientific or artistic domain of activity. Lines and colors are basic elements of design. 6...
百度试题 题目What is the atomic number of oxygen?A、2B、6C、8D、20Answer:C 科目四考试网___科目四考试题库相关知识点: 试题来源: 解析 http://www.km4ks.com/st/tk/ 反馈 收藏
The basic structure of silicone is made up of polyorganosiloxanes, where silicon atoms are linked to oxygen to create the «siloxane» bond.
Photosynthesis is a chemical reaction in which water (H2O) and carbon dioxide (CO2) chemically react to form the simple sugar glucose (C6H12O6) and oxygen gas (O2). What mass of oxygen gas is produced by the reaction of 5.2 g of water? Be...
The human body contains around 20 different elements, mostly made inside ancient stars. If you deconstructed an 80kg human into atoms, you would get about the following amounts of the different elements: Oxygen – 52kg This element makes up more than half the mass of your body but only a...
Sample return could also be achieved as part of a more ambitious, extended mission to study the venusian atmosphere. In both scenarios it is critical to obtain a surface atmospheric sample to define the extent of atmosphere-lithosphere oxygen isotopic disequilibrium. Surface sampling would be carried...