If a historian wanted to determine whether iron tools could be found in the ruins of an ancient african city, which kind of expert should he consult?

Archaeologist

Explanation:

For a historian, it is necessary to identify the iron tools from the ancient ruins by consulting archaeologist. Archaeologist studies early human history through findings from the excavation sites and also by analysis of artifacts. They also go to different historical places to analyze by studying the scriptures, tools and the culture of the people living there.  

special interest groups must step back and let the process work itself out a representative can amend it at several points in the congressional staffers must do homework and report to the floor on what they 've learned

answer; andrew jackson approved nullification by signing it into law,and john calhoun opposed it saying it was unconstitutional;