She felt light-hearted and optimistic.

她感到无忧无虑，很乐观。

《牛津词典》

You will feel more buoyant and optimistic about the future than you have for a long time.

对于未来，你会比很久以来所感受到的更加快活、乐观。

《柯林斯英汉双解大词典》

Only being strong and optimistic can one go through difficulties.

一个人只有保持坚强和乐观，才能克服重重困难。

youdao

The study also found that women who were not optimistic were more likely to smoke and have high blood pressure or diabetes.

VOA: special.2009.04.15

If I charged the reactor in this manner, and of course I'm assuming 100% completion of the reaction which we know is overly optimistic.

如果我们这样来考虑这个反应的前提，就是我们假设,反应完全进行,我们知道这有些过于乐观了。

麻省理工公开课 - 固态化学导论课程节选

As we saw in the last lecture, the elder brother holds an entirely different theory of chastity, and of course, it's a lot more optimistic.

我们上一讲中看到,年长的哥哥对贞节有完全不同的看法，当然那是乐观许多的。

耶鲁公开课 - 弥尔顿课程节选

Like Mr Miller, Mr Mason's success has been based on making unusual and optimistic bets.

ECONOMIST: The rise of an American broking firm

It's not easy, but at 49, Jack remains determined, at turns realistic and optimistic.

CNN: From Wall Street to the street: A cabdriver's tale

"We remain calm and optimistic, " said the Spaniard, who dropped from third to fourth in the championship.

BBC: Ferrari will bounce back, says Fernando Alonso