they have been trying to find out how the fire began.句子成分怎么分...?how the fire began是find out的宾语,那从整个句子来看成分怎么分呢?谢谢.
问题描述：
they have been trying to find out how the fire began.句子成分怎么分...?how the fire began是find out的宾语,那从整个句子来看成分怎么分呢?谢谢.
答
What caused the fire? At last firemen have put out a big forest fire in California. Since then, they have been trying to find out how the
答
主 谓 宾 [ 宾语从句]
（they ）（have been trying） （to find out [how the fire began].）
to find out how the fire began 动词不定式在整个句子中作宾语