Make sure you are sitting up straight.

确保你坐直了。

youdao

That's right, sitting up straight can help you do better on math exams.

没错，坐直可以帮助你在数学考试中取得更好的成绩。

youdao

But another part wonders what's next after sitting up straight.

但另一部分又怀疑，坐端正之后又会发生什么呢？

youdao

I think even if you're in a chair, and you're sitting up straight with good posture, maybe hands on knees.

哪怕只是坐在椅子上，坐直并保持良好姿势，也许双手放在两膝上。

普林斯顿公开课 - 人性课程节选

Whenever he came home, he found her in the living room, sitting up straight on the couch.

NEWYORKER: Creative Writing

The Uprightsleeper looks like a neck brace the kind worn to immobilize the cervical spine after a traumatic injury (although it "makes no medical claims") and facilitates sleeping while sitting straight up.

WSJ: The Best Travel Pillows: Desperately Seeking Slumber