You would never guess (that) she had problems. She's always so cheerful.

你怎么也猜不到她有难以解决的问题。她总是那么乐观。

《牛津词典》

I am so cheerful and yet so sad that my tears reflect at once both heaven and earth.

我是如此兴高采烈，而又如此悲伤，以至于我的眼泪立刻映出了天地。

youdao

So cheerful and continued giving is a sign of love and evidence you care for others.

因此喜乐地持续的给予是爱的标志和你关心其他人的证据。

youdao

"I am sorry because the crew of mostly local East Anglians was so cheerful, professional and delightful to work with, " he said.

BBC: ITV cancels Stephen Fry's Kingdom

Not surprisingly for a man so charming and cheerful, he liked the ladies, and they liked him (he didn't marry until late in life).

FORBES

So let's be cheerful and talk about a few where you feel you were spectacularly right.

FORBES: Dow Jones Interactive