小女孩骑在爸爸的肩膀上过河。

The little girl ___piggybacked on her dad's shoulders to cross the river.

这个新功能借助现有的支付系统来实现快速交易。

The new feature ___piggybacked on the existing payment system to enable fast transactions.

他们在会议议程的最后临时附加了一个小提议。

They ___piggybacked a small proposal onto the end of the meeting agenda.