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。

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Portrait mode is optional.

竖屏模式是可选的。

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Portrait mode chooses a large aperture (a small 'f' number) which will make the depth of field (the amount of your shot in focus) smaller.

人像模式用一个大光圈(f值小)，而让景深(清晰对焦的那部分)变小。

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In addition, there is no way to use the supplied keyboards in portrait mode.

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For example, turning the device into portrait mode makes room for custom suggestions.

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In portrait mode they are more like a traditional (if large) TV remote.

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