certificate (usually of proof of something) credentials

sponsor, promoter, impresario, organizer, organiser

to bury in the ground

to bury (e.g. in the ground), to fill up (e.g. audience fills a hall), to cause to be packed, to plug (a gap), to stop (a gap), to bridge (a difference, a gap), to fill (a seat, a vacant position), to fill out, to make up for (a loss, shortage, etc.), to make amends, to compensate for, to put cold water (in a bath), to cover, to scatter something over

steering, piloting, flying, control, operation, handling, management, handling, control, manipulation

pilot

slick, slippery, smooth, sleek, slurping (noodles)

stock, share, stump, root, rootstock, strain (of bacteria, etc.), tradeable rank, goodwill, one's forte

self-sufficiency

obstacle, impediment, hindrance, difficulty, barrier, handicap, impairment, disability, disorder, malfunction, impairment, failure