The plane had taken off when i reached the airport

问题描述:

The plane had taken off when i reached the airport
改为同义句
The plane_____off______I reached the airport.

the plane took off before i reached the airport.
原句的意思是,当我到机场的时候飞机已经起飞了,也就是在我到机场之前飞机就起飞了,恰好是改写的句子