Step by Step 3000 第1册 Unit12:Dictation item(8)

 　　Item eight.

　　Vocabulary. fossil, molecule¹, hydrogen, carbon, sulfur².

　　Petroleum³ has been important since ancient times.

　　In Latin, the name means "rock oil".

　　Petroleum is a fossil fuel.

　　The liquid comes from the remains⁴ of plants and animals that died millions of years ago.

　　These remains were buried deep bellow⁵ levels of rock over time and under great pressure.

　　This geological process created complex molecules⁶ of hydrogen and carbon.

　　Oil can also contain other elements.

　　Crude oil or unprocessed petroleum is called sour when it contains a lot of sulfur and impurity⁷.

　　Sour crude requires more refining than sweet crude which is often more valuable.

1 molecule   

n.分子，克分子

参考例句：

• A molecule of water is made up of two atoms of hygrogen and one atom of oxygen.一个水分子是由P妈̬f婘̬ 妈̬成的。
• This gives us the structural formula of the molecule.这种方式给出了分子的结构式。

2 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

3 petroleum   

n.原油，石油

参考例句：

• The Government of Iran advanced the price of petroleum last week.上星期伊朗政府提高了石油价格。
• The purpose of oil refinery is to refine crude petroleum.炼油厂的主要工作是提炼原油。

4 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

5 bellow   

v.吼叫，怒吼；大声发出，大声喝道

参考例句：

• The music is so loud that we have to bellow at each other to be heard.音乐的声音实在太大，我们只有彼此大声喊叫才能把话听清。
• After a while,the bull began to bellow in pain.过了一会儿公牛开始痛苦地吼叫。

6 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

7 impurity   

n.不洁，不纯，杂质

参考例句：

• The oxygen reacts vigorously with the impurity in the iron.氧气与铁中的杂质发生剧烈的化学反应。
• The more general impurity acid corrosion faster.一般来说杂质越多酸蚀速度越快。