their best
They are doing their best.
They did their best.
They're doing their best.
Les gens devraient faire de leur mieux.
People should do their best.
Tous les joueurs ont fait de leur mieux.
All the players did their best.
Le père Noël et maman feront de leur mieux.
Santa Claus and Mom will do their best.
— Piège de cristal (1988)