1、be quick to （这里的to是介词还是不定式符号？）
2、The history of written Chinese goes back at least 4,000 years,_____ of English little more than 1,000 years.
A、which B、it C、one D、that
这题楼主错选C，求解释。
3、Don't call him between 8:00 and 10:00 tomorrow.He ________ his classes then.
A、has B、had C、is having D、will be having
这题楼主错选D，因为觉得是在明早八点到十点中，他正在上课……不过要是没学这个时态肯定不选了，这种问题怎么破！（并求讲解这题）
2、The history of written Chinese goes back at least 4,000 years,_____ of English little more than 1,000 years.
A、which B、it C、one D、that
这题楼主错选C，求解释。
3、Don't call him between 8:00 and 10:00 tomorrow.He ________ his classes then.
A、has B、had C、is having D、will be having
这题楼主错选D，因为觉得是在明早八点到十点中，他正在上课……不过要是没学这个时态肯定不选了，这种问题怎么破！（并求讲解这题）
