GRE Reading Comprehension: ETS-GRE阅读ETS - 193PBUE2G41XKV077

The primary purpose of the passage is to A. describe the way in which hot spots influence the extinction of volcanoes B. describe and explain the formation of the oceans and continents C. explain how to estimate the age of lava flows from extinct volcanoes D. describe hot spots and explain how they appear to influence and record the motion of plates E. describe the formation and orientation of island chains in the Pacific Ocean