在 How they will manage to do it remains to be seen.中：在 they will manage to do it remains to be seen.中：they will manage to do it 是主语,be seen 是谓语,那么remains to 是什么?
问题描述：
在 How they will manage to do it remains to be seen.中：
在 they will manage to do it remains to be seen.中：they will manage to do it 是主语,be seen 是谓语,那么remains to 是什么?
答
目的状语
答
你理解错了
主 - How they will manage to do it
谓 - remains to be seem
这句话想表达的是 ___ remains to be seem.(___ 还待观察)
所以How they will manage to do it（他们会怎样解决问题）整个都是remains to be seem的主语。
答
这是一个主语从句
they will manage to do it这个从句做主语
remains是系动词
to be seen是不定式做表语
就是主+系+表 的句型结构