1. But the optimism was short-lived.
    然而，人们不久就不再感到乐观了，

2. By now optimism had given way to doubt.
    至此，人们不再乐观，反而疑虑重重。

3. He was still full of optimism for the future despite his many problems.
    他尽管有许多问题, 但对未来仍十分乐观.

4. Martin Seligman of the University of Pennsylvania advised the Metlife insurance company to hire a special group of job applicants who tested high on optimism, although they had failed the normal aptitude (才能) test.
    宾夕法尼亚大学的马丁·塞利格曼建议梅特莱夫保险公司雇用一批特别的求职者，他们经测试证实有很乐观的心态，虽然在一般能力测验上不及格。