他们在飞机上坐在我们后面。

They sat ___in ___back ___of us on the plane.

我向身后看去，看到了我最好的朋友在笑。

I looked ___in ___back ___of me and saw my best friend laughing.

车停在房子后面。

The car is parked ___in ___back ___of the house.