side frame top chord

例句：

1. 1. This side frame is designed to fit perfectly into the wall.
   这个侧面框架设计得可以完美地嵌入墙中。
2. 2.The top chord of the guitar is where the strings attach.
   吉他的顶部弦是弦线附着的地方。
3. 3. The engineer used a side frame and top chord to reinforce the structure.
   工程师使用了侧面框架和顶部弦来加固结构。