Changing diapers is the most important and crucial responsibility of both parents. (checkpregnancy.com)
It's hard to pick just one out of the infinite possibilities out there, but it's also one of the most crucial responsibilities held by all parents. (babygaga.com)
That means he should accept your touch and handling without resistance, a basic and crucial responsibility for you to work on by holding a nut or treat in your hand, in the cage, and waiting for the hamster to learn to step onto your hand. (animals.mom.me)