[求助]请教改错题一道

coolerdavid

Wampum, beads used as a form of exchange by some Native Americans, was made of bits of seashell cut, drill, and strong into belts.

    

Answer: D. 为什么呀

真老九

drill>>>drilled

Wampum, beads used as a form of exchange by some Native Americans, was made of bits of seashell (which is)cut, drilled, and strong into belts.

coolerdavid

thank you very much!