How did the location of mineral resources and the Rhine River help Ruhr Valley become a densely populated manufacturing region? NO LINKS please!!!

Which examples are relevant sources for students to use in research? check all that apply. a journal entry written by a professor who is considered an expert a report written by an independent government source a presentation by a company that includes paid information a document published by a renowned organization a scientific paper put out by a non-profit organization a blog whose author tries to sell a product or service