他换成了一个挺直的姿势。

He moved into an upright position.

《柯林斯英汉双解大词典》

当您呼气时，尽量保持挺直的身姿。

As you exhale simply maintain that upright position.

youdao

如果在跑步过程开始向前弯腰，那你需要加深呼吸，有意的挺直，随着呼气你就能保持挺直的姿势。

If you start to slouch during a run take a deep breath and feel yourself naturally straighten. As you exhale simply maintain that upright position.

youdao

When I see birches bend to left and right Across the lines of straighter darker trees, I like to think some boy's been swinging them.

当我看到白桦树弯下身子，向左，也向右,穿过排列成行的挺直黑黑的树，我总以为有个孩子把白杨“荡“弯了。

耶鲁公开课 - 现代诗歌课程节选

And, yet, think about the qualities of sound that are so different between "across the lines of straighter darker trees" and "I like to think some boy's been swinging them."

想想这音律的特别之处,这两句有很大的区别,“穿过排列成行的挺直黑黑的树“,我总以为有个孩子把白杨“荡“弯了“

耶鲁公开课 - 现代诗歌课程节选

SK 2007 has still got his hair, has the beard, stands up more or less straight.

我在2007年还有头发，有胡子，站得挺直的。

耶鲁公开课 - 死亡课程节选