英语翻译

问题描述:

英语翻译
The boy was walking down the street when the UFO landed.
While the boy was walking down the street,the UFO landed.
The girl was shopping when the alien got out.
While the girl was shopping,the alien got out.

当飞碟着陆的时候,那个男孩正沿着*大街行走.
当那个男孩在沿着*大街行走的时候,飞碟着陆了.
当外星人走出来时,那个女孩在购物.
当女孩在购物的时候,那个外星人走出来了.