4. 大多數人都熟悉這樣一個概念，物質是由叫做原子的極小粒子組成的。
Most people are familiar with the idea that matter consists of very small particles called atoms.
5. 一星期由七天組成。
A week consist of seven days.
6. 混合物由兩種或更多彼此不發(fā)生化學合成并能被分開的物質組成的合成物
A composition of two or more substances that are not chemically combined with each other and are capable of being separated.
7. 馬氏本，馬登斯體一種由鐵和高達百分之一的碳組成的溶液，是硬化碳工具鋼的主要成分。
A solid solution of iron and up to 1 percent of carbon, the chief constituent of hardened carbon tool steels.
8. 鑒于稅務原因，我們得組成公司。
We had to incorporate for a company for tax reasons.