这句话的句子成分怎么划分啊.?

问题描述:

这句话的句子成分怎么划分啊.?
The initial discovery by humans almost 10,000 years ago that they could exploit metallic mineral deposits was an important milestone in the development civilization.

"The initial discovery "(是主语)by humans almost 10,000 years ago that they could exploit metallic mineral deposits was(是谓语) an important milestone(是宾语) in the development civilization.