判别句子结构

1. “是个” $ \implies $ 主系表

2. “以$ \cdots $ 而出名” $ \implies $ 主系表 are famous / well-known for

famous as 作为什么而出名 ❌

1. “一直在” $ \implies $ 主系表 has been

2. “已经成为” $ \implies $ 主系表 has become