1.He never takes the bus home.
= He never goes home by bus.
= He never goes home on the bus.
2.They sometimes go to the zoo by bike.
= They sometimes ride bikes to the zoo.
= They sometimes cycle to the zoo.
3.on foot和walk同义句变化例句：
He never walks home.= He never goes home on foot.
They sometimes go to the zoo on foot.= They sometimes walk to the zoo.