acknowledgement

n. 承认,确认,感谢,收到的通知

achieve, achieve one's goals, achievement, achiever, Achilles, Achilles' tendon, aching, achromatic, achy, acid, acid rain, acidic, acidify, acidity, acidly, acidosis, acidulated, acidulous, acknowledge, acknowledged, acknowledgement (also acknowledgment), acknowledging, acknowledgment, acme, acne, acolyte, aconite, acorn, acoustic, acoustically, acoustics, acquaint, acquaintance, acquaintant, acquainted, acquaintence, acquiesce, acquiescence, acquiescent, acquire,