他十六岁，无忧无虑。

He was sixteen years old and didn't have a ___care in the world.

那一刻，她感到自由，毫无牵挂。

At that moment, she felt free and didn't have a ___care in the world.

尽管责任重重，他似乎总有心事。

With all his responsibilities, he always seems to have a ___care on his mind.