Their yawning seems to have nothing to do with sleepiness or boredom—quite the reverse—but it does precede a change in activity level.

他们打哈欠似乎与困倦或者无聊没有任何关系，但恰恰相反，打哈欠这一行为的确出现在了活动水平的变化之前。

youdao

He was not at all jolly. Quite the reverse.

他一点儿也不高兴。恰恰相反。

《柯林斯英汉双解大词典》

It wasn't easy to persuade her to come— quite the reverse.

说服她过来不容易—实在太难了。

《牛津词典》

Quite the reverse, in fact: In 12 months, the FTC has only publicly announced two investigations.

FORBES: FTC Official: "Hard to Measure" Impact of Blogger Guidelines

Quite the reverse: modern American politicians either need to be wealthy, or need the financial backing of the rich.

ECONOMIST: Voters are now facing a harsh truth

"I think it's economic madness, and no other major government in the world is considering this, quite the reverse".

BBC: Cameron makes savings tax pledge