Complex sentence: He has lectured in Russia, Spain, Tanzania, and at several institutions in the U.S. and Canada and was visiting professor at George Washington University and Marquette University and Director of Telecommunications at Dean College.
Split into simpler sentences: He has lectured in Russia, Spain, Tanzania, and at several institutions in the U.S. and Canada. Keith served as a visiting professor at George Washington University and Marquette University and Director of Telecommunications at Dean College.