I rarely used the four physical buttons at the bottom of the screen (in portrait mode) for locking the screen, browsing, returning to a previous screen, and returning to the home screen.

屏幕底部的四个物理按键在肖像模式下分别用于锁定屏幕、浏览、返回上一屏幕以及并返回主屏幕，但我很少使用。

youdao

I rarely used the four physical buttons at the bottom of the screen (in portrait mode) for locking the screen, browsing, returning to a previous screen, and returning to the home screen.

屏幕底部的四个物理按键在肖像模式下分别用于锁定屏幕、浏览、返回上一屏幕以及并返回主屏幕，但我很少使用。

youdao