perishable adj. （食物）易腐烂的，易变质的；（抽象事物）易消亡的，短暂的 例句Perishable food should be stored in a refrigerator. 易腐的食物应储存...
optimistic名词optimism n.乐观;乐观主义optimisticadj.乐观的;抱乐观看法的派生词 optimistically (adv.) 例句 A mood of optimism swept through the comp...
