optimistic名词：optimism

n.乐观;乐观主义

optimistic

adj.乐观的;抱乐观看法的

派生词： optimistically (adv.)

例句：

A mood of optimism swept through the company and its customers.

公司上下及其顾客都洋溢着一股乐观情绪。

Optimism was gradually taking the place of pessimism

乐观情绪逐渐取代了悲观主义。

only time will tell whether Broughton's optimism is justified

只有时间会验证布劳顿的乐观是否合理。