1. firmly
2. severely
3. heavily

1. intemperately, difficult
2. ambitious, challenging, arduous, awkward, embarrassing, sticky, unenviable, baffling, knotty, problematic, problematical, catchy, tricky, delicate, ticklish, fractious, hard-fought, Herculean, nasty, tight, rocky, rough, rugged, tough, stubborn, tall, thorny, troublesome, trying, vexed, serious, demanding, effortful, hard
3. brutal, cruel, harsh, rigorous, unkind, calculating, calculative, conniving, scheming, shrewd, case-hardened, hardened, hard-boiled, steely, stiff, uphill, difficult, insensitive, merciless, unmerciful, tough, hard
4. adamantine, al dente, corneous, hornlike, horny, erect, tumid, firm, solid, granitic, granitelike, rocklike, stony, hardened, set, lignified, woody, marmoreal, marmorean, ossified, petrified, petrous, stonelike, slaty, slatey, steely, unpadded, semihard, solid, knockout
5. severe, strong, arduous
6. backbreaking, grueling, gruelling, heavy, laborious, punishing, toilsome, effortful, hard
7. plosive, velar, heavy
8. intemperate, fermented
9. soured, strong
10. alcoholic, tough
11. bad, stale