这种虱子会寄生在狗的皮肤上，导致剧烈瘙痒。

These lice ___parasitize dogs' skin, causing intense itching.

有些公司利用实习生免费劳动，这是一种不公平的剥削行为。

Some companies ___parasitize interns by making them work for free, which is unfair exploitation.