GRE Text Completion: JiJing 1373-GRE填空机经1373题 - 4TF5Y7G72MZ2VAQBA

At Cerro Portezuelo, the task of separating grinding tools from the larger collection of excavated stone objects was (i)____________ the ancient practice of recycling grinding tool fragments for building materials, hammer stones, and other purposes that (ii)____________ their original use. A. complicated by B. complemented C. important to D. obscured E. independent from F. underscored