他宁愿自己粉刷房子——这是一项辛苦但乐在其中的工作。

He prefers to paint the house himself - it's ___a ___labor ___of ___love.

写这部小说对她来说是一项辛苦但乐在其中的工作。

Writing this novel was ___a ___labor ___of ___love for her.

园艺对许多退休人士来说是一项辛苦但乐在其中的活动。

Gardening is ___a ___labor ___of ___love for many retirees.