the only thing they have in common is electric propulsion.3922

the only thing they have in common is electric propulsion.3922
想知道的语言点：
1—the only thing：怎么翻译.
2—the only thing 和 they 事什么关系?
they have 中 have 表示具有，拥有
they have 做the only thing定语从句。修饰the only thing
the only thing 唯一的事情，仅有的事情
the only thing they have ：他们具有唯一的事情
the only thing they have in common ：他们具有唯一的（事情）的共同点。
翻译：他们具有唯一的共同点是电力推动。