1. My english teacher is extremely strict about grammar, i dare not talk with him unless i get every grammatical point straight in my mind.
2. glass-making was practiced thousands of years ago by egypitans though it was many centuries before men discovered how to make glass transparent.
3. while divorce is often the only satisfactory solution for married couples who can no longer stand the sight of each other, it can have a shocking effect on their kids.
參考答案:1.我的英语老师在语法方面真是非常严厉，除非是我心里有一些纯语法的问题，否则我根本不敢跟她说话。
2.尽管在几个世纪以前人们才发现了如何制造出纯净的玻璃，然而埃及人却在几千年前就已经熟练地掌握了玻璃制造法
3.尽管对于相互已经无法容忍对方的夫妻来说，离婚通常是唯一令人满意的解决房案，但它却会对孩子产生令人震惊的巨大影响
