大楼的前门半开着，所以我走上楼梯，按了门铃，等待着。

The front door of the building stood ajar, so I went up the stairs, rang the bell, and waited.

youdao

大楼的前门半开着，所以我走上楼梯，按了门铃，等待着。

The front door of the building stood ajar, so I went up the stairs, rang the bell, and waited.

youdao