阅读段落

　　Glass, which has been made since the time of Mesopotamians and Egyptians, is little more than a mixture of sand, soda ash and lime. When heated to about 1500 degrees Celsius this becomes a molten mass that hardens when slowly cooled. The first successful method for making clear, flat glass involved spinning. This method was very effective as the glass had not touched any surfaces between being soft and becoming hard, so it stayed perfectly unblemished, with a fire finish. However, the process took a long time and was labour-intensive.

　　段落大意

　　本段介绍了最早制作透明光滑的玻璃的方法，并指出该方法耗时耗力。

　　阅读笔记

　　Glass production:

　　Time: Mesopotamians and Egyptians

　　Composition: a mixture of sand, soda ash and lime

　　Method: 1.heated to 1500 degrees Celsiusa molten mass hardens when slowly cooled

　　2. first successful method for making clear, flat glass involved spinning

　　3.effective HOWEVER time-consuming and labour-intensive

　　逻辑关系

　　1. 因果

　　The glass had not touched any surfaces between being soft and becoming hard, so it stayed perfectly unblemished, with a fire finish.

　　This method was very effective.

　　2. 对比

　　This method was very effective.

　　The process took a long time and was labour-intensive.

　　阅读段落

　　Glass, which has been made since the time of Mesopotamians and Egyptians, is little more than a mixture of sand, soda ash and lime. When heated to about 1500 degrees Celsius this becomes a molten mass that hardens when slowly cooled. The first successful method for making clear, flat glass involved spinning. This method was very effective as the glass had not touched any surfaces between being soft and becoming hard, so it stayed perfectly unblemished, with a fire finish. However, the process took a long time and was labour-intensive.

　　段落大意

　　本段介绍了最早制作透明光滑的玻璃的方法，并指出该方法耗时耗力。

　　阅读笔记

　　Glass production:

　　Time: Mesopotamians and Egyptians

　　Composition: a mixture of sand, soda ash and lime

　　Method: 1.heated to 1500 degrees Celsiusa molten mass hardens when slowly cooled

　　2. first successful method for making clear, flat glass involved spinning

　　3.effective HOWEVER time-consuming and labour-intensive

　　逻辑关系

　　1. 因果

　　The glass had not touched any surfaces between being soft and becoming hard, so it stayed perfectly unblemished, with a fire finish.

　　This method was very effective.

　　2. 对比

　　This method was very effective.

　　The process took a long time and was labour-intensive.