在收容所做志愿者是一种有益的体验。

Volunteering at the shelter is a ___rewarding experience.

教学是艰苦的工作，但非常有回报。

Teaching is hard work but it's very ___rewarding.

带领儿童工作坊是一次非常有益的体验。

Leading a workshop with children was a very ___rewarding experience.