piggybacks
n．背马：一个人背着另一个人，通常是一个成年人背着一个孩子。
v．背马式搭载：将一个物体放在另一个物体上进行运输。
例句
He piggybacks on other hosts and USES their resources to increase his tribe.
他寄生在其他宿主身上，并利用宿主的资源繁衍自己的后代。
Google has published a convention that piggybacks on the robots.txt convention.
google在robots . txt约定的基础上发布了一个新的约定。
Curapipe’s system piggybacks, as it were, on the system of “pigs” commonly used to clean urban water mains.
Curapipe公司开发的新系统（和过去一样）依附于广泛用于清洁城市输水管道的“好猪”系统。
