back什么意思？

“back”，名词，意思是“背后，背部，后面”，例如“He was lying on his back.”“他正在仰面躺着”。也可作为副词，意思是“往后地，向后地”，例如“She stepped back from the door with a scary face.”“她一脸惊恐地退到了门外”。常见的短语有“back and forth（来来回回地）”，“have your back（支持你）”。