Explore the moon has many benefits. Mine on the Moon, 40% the oxygen content of soils and sufficient 7000 power helium-3 elements of the Earth. By detecting, preparing for human exploitation of lunar resources to ease the human earth pressure, enhancing human living. ...
答案:D more>> most分析:考点是最高级的使用;由于有 Of all the elements 对比较范围进行了限定,因此要用最高级,将 more 改为 most;全句也是一个倒装结构,正常的语序是 Oxygen is known to be the most common of all the elements in the Earth’s crust.翻译:在地壳的所有元素中,氧被认为是最多的。
Geoffrey Himes
The creation of life requires a set of chemical elements for making the components of cells. Life on Earth uses about 25 of the 92 naturally occurring chemical elements, although just 4 of these elements oxygen, carbon, hydrogen, and nitrogen make up about 96 percent of the mass of living ...
the bays.The chondrite-normalized distribution patterns show the typical enrichment of light REEs(La to Eu) relative to heavy REEs(Gd to Lu),and an apparent depletion of Eu,which is diagnostic of a terrigenous sediment source.Obvious enrichments of the middle REEs(Sm to Ho) in the PAAS-...
托福tpo54阅读第3篇ElementsofLife题目解析 Asomewhatstricter requirement is the presence of these elements in moleculesthatcan be used as ready-made building blocks for life, just as early Earth probably had an organic soup of amino acids and othercomplexmolecules building blocks of live 生命基石 ...
In order to recover the rare earth elements (REEs) from neodymium permanent magnet scraps, Fe 2 O 3 , B 2 O 3 , and FeO–B 2 O 3 fluxes were designed to extract the REEs. The REEs containing oxides were successfully separated from the Fe-based metals at the temperatures of 1,673,...
Shortly after sampling, rare earth elements (REEs) from 11.5 l of seawater were concentrated in 35 ml solutions by ion exchange chromatography on board the German research vessel ''Sonne'' using Chelex 100 chelating resin for preconcentration. Two millilitres of a 0.2 μg gLu spike was added ...
Tipping elements are components of the Earth system that may shift abruptly and irreversibly from one state to another at specific thresholds. It is not well understood to what degree tipping of one system can influence other regions or tipping elements.
The effects of rare earth elements on the microstructure and properties of magnesium alloy AZ91D alloy were studied. The different proportion of rare earth elements was added to the AZ91D and the tensile tests were carried out at different temperatures. The experimental results show that at room ...