by itself

单独地, 独自地

例句与用法：

If air is needed, the oxygen mask in the plane will pop down by itself.

如果空气缺乏，飞机内的氧气面罩会自动放下。

The house stood by itself on a hill.

这座房屋独立在小山上。

The machine will start by itself in a few seconds.

机器在几秒钟後会自动开启。

The statue stands by itself in the square.

广场上孤零零地立著这座雕像。

详细释义：

1. 自动地

The machine works by itself.

机器自行运转。

2. 单独地

The farmhouse stands by itself in the fields.

农舍孤零零地坐落在田间。