本题考查定语从句,先行词是air。,本句可分为两个单句: Air is a mixture of gases(空气一种气体混合物),和 Oxygen forms 21% by volume of air(氧气按体积占空气的21%),of表示范围,which代指ai,rin 表示地点或时间,to表示方向,by表示方式,所以答案是D ...
- **A. variety**:意为“种类”,常以“a variety of”形式出现,表示“多种多样的”,但填入后句意变为“空气是气体的一种类别”,不符合科学事实。 - **B. mixture**:意为“混合物”,指不同物质物理混合且保留各自性质。空气由氮气、氧气等气体混合而成,属于混合物,与“mixture”完全契合。 - **C. ...
a...清清姑娘是这么说的。 ...The clear clear girl is such says.[translate] aAir is a mixture, whose components are of great use in chemical plants. 空气是混合物,组分有用巨大在化工工厂中。[translate]
解答答案:mixture 根据a___of gases,可知应该用名词形式.mix,动词,混合.名词形式,mixture,混合物.a+可数名词单数,故填:mixture. 点评本题主要考查可数名词单数,名词形式,mixture,混合物.a+可数名词单数,要注意名词形式. 练习册系列答案 天天练习王口算题卡口算速算巧算系列答案 育才...
英语语法问题We have learned that air is a mixture of gases,___oxygen,water,vapor and carbon dioxide are the most important for what they do.A.whoseB.in whichC.of whichD.where答案选的是C,想问下为什么不能选D,另外介词为什么
【知识点拨】 本题主要考查可数名词单数,名 词形式mixture混合物.a+可数名词单数, 要 注意名词形式。 【分析】 根据a..of gases,可知应该用名词形 式.。 mix动词, 混合。 名词形式, mixture, 混 合物。 a+可数名词单数, 故填:mixture 反馈 收藏 ...
Air is a mixture of gases(空气是气体的混合物)。 A. variety(种类)— 通常与“of”搭配表示多种,但不符合此处需要“混合”的语境。 B. mixture(混合物)— 正确,空气由多种不同气体(如氮气、氧气等)物理混合而成。 C. extension(扩展)— 不符合题意。 D. combination(组合)— 强调“结合体”,多用于...
aAir is a mixture of gases, consists mainly of nitrogen and oxygen, by volume, about 78% of the nitrogen in the air, oxygen and inert gas accounted for 21%, accounted for 0.94, accounting for about 0.03 of the carbon dioxide, water vapor and impurity accounted for about 0.03 of the. ...
Glenn Branch, the centre's deputy director, cautions that setting state-level science standards is only one limited benchmark in a country that decentralises decisions to local school boards. Even if a state is considered a high performer in its science standards, "that does not mean it will...
the element 'oxygen' is part of the mixture 'air' and some of the properties of air are due to the oxygen part - but those properties are generally less strong / intense than those of pure oxygen because of the presence of the other constituents of the mixture called 'air', e.g. ...