Question

英语语法问题请教。。。谢谢了

They thought it their duty to keep Eric in hiding.

请大家帮忙分析一下这句话的句子成分和结构（越细越好）谢谢大家的指点说明。。

Answer 1

这是个简单句
They 主语
thought 谓语
it 是形式宾语
their duty 宾语补足语
to keep Eric in hiding 动词不定式短语作真正的宾语。