背墙

例句：

1. 1. She stood against the wall, facing the door.
   她背对着墙，面对着门。
2. 2. The artist painted on the wall with a brush.
   艺术家用刷子在墙上作画。
3. 3. He worked on his project by writing in the margins of the book.
   他通过在书的边缘写东西来完成他的项目。