婴儿吮吸他的拇指。

The baby ___sucked his thumb.

孩子们经常把吮吸棒棒糖当作一种享受。

Children often ___suck on lollipops as a treat.

他会吮吸手指来翻日记的页。

He would ___suck his fingers to turn the pages of the diary.