軟: soft

難問: difficult problem / 南門: south gate

これは何ですか: what is this?

firmness, strength / stability, security

firm, strong / stable, secure

(informal, men's speech) you (plural)

et tu, Brute

共晶: eutectic composition / 協商: (diplomatic) agreement / 狭小: quality of being narrow / 胸章: a badge / 胸墻: breastwork / 橋床: the deck of a bridge / 競翔: pigeon racing / 強将: a strong leader, a brave general

狭小: narrow, small

経典: sutra