雅思英语类别: 雅思口语一对一陪练,托福口语,日常英语口语,商务英语口语,以及幼儿英语口语。 如下为同学雅思原文: Essay: These flowcharts provide an overview of the steps and machines of cement-making process and how to use cement to produce concrete for building purposes. The cement production process involves three main stages. First, the crusher grind limestone and clay to powder which will be conveyed to mixer. After mixed, the Rotating heater spin them, meanwhile the heat hot up them to another kind of powder. Next, these solids should be squeezed to the cement by a grinder and packed into bags. Different from complex previous step, the concrete production only have one stage. The final product be make up of 15% cement, 10% water, 25% sand and 50% Gravel which is a category of small stones. Only by put them into a big concrete mixer which will revolve and mix these materials for a long time, then we can get the concrete. Finally, these things can be used to construct the constructions. 如下为外教修改后的作文: |