ac,acr,acid = sour(酸的)sharp(锋利的)acuity(锋利的性情ac(=sharp))n.锋利;激烈;灵敏acute adj.灵敏的;锋利的;激烈的;急性的acumen n.灵敏;锋利Only soldiers with perfect visual acuity can be絲路旅遊, trained to be fighter pilots. 只有那些视敏度绝好的兵士才能被练习成战役机飞翔员。
acrid adj.(气息等)刺激的;辛辣的;(言语等)刻薄的,调侃的acrid smell of burning feathers 烧羽毛的刺鼻气息