a tree一棵树aart.一(个)；每一(个)；任一(个)n.英语字母表的第一个字母；学业成绩得优者；表示“最好”的符号A screaming jet plane.呼啸的喷气式飞机。a vessel to retain water盛水的容器A cat retracts its claws猫缩进它的爪子。a slight attack of fever一点发烧a smallish town/child相当小的城镇；个头颇小的孩子a horde of mosquitoes.一群蚊子。a gossamer justification站不住脚的辩解a thermosetting resin.一种热硬化性的树脂。a vast expanse of desert浩瀚的沙漠A Postcard from New York来自纽约的明信片