Tenaciously

As he pulled laundry from the dryer, Tom saw that because of static electricity a grey sock clung tenaciously to a facecloth.

He continued tenaciously, doggedly continuing over all obstacles.

[…] tens of thousands of other foot passengers have been slipping and sliding since the day broke (if this day ever broke), adding new deposits to the crust upon crust of mud, sticking at those points tenaciously to the pavement, and accumulating at compound interest.