当我做作业是有人敲门用英语怎么说

问题描述:

当我做作业是有人敲门用英语怎么说
还有:昨天下午一个外星人参观了博物馆
当妈妈下班回家时,你在干什么?
请你用英语全部翻译一下

When I do my homework someone knocking at the door
Yesterday afternoon aliens visited the museum
When mother came home from work, what are you doing?