请教大大
以下差别在哪？怎么翻译？
1. When we arrived , she made some coffee.
When we arrived , she was making some coffee
2. I read a good book last night.
I was reading a good book last night.

When we arrived , she made some coffee. 表示两件事发生的时间差不多，冲咖啡可能还稍微晚一点。When we arrived , she was making some coffee. 则强调两件事发生的时间有重叠。I read a good book last night. 只是简单地叙述我昨晚作了什么事。I was reading a good book last night. 还有多表达那件事用掉了我一些时间的意思。