to compensate; to make up

to replenish; to supplement; to complement; additional; supplementary; CL:個|个[ge4]

supply; replenishment; to replenish

to remedy

to take extra lessons in a cram school or with a private tutor

to complement; to make up for a deficiency

to fill a gap; to fill in a blank (on a form); to overcome a deficiency

to mend

to replace (a damaged component with a new one, an injured player with a substitute player, full-time workers with casual workers etc); a substitute; a replacement

to wait to fill a vacancy; reserve (candidate); alternate; substitute