D: Many firms in the metalworking industry have moderized production equipment in the last five years , and most of these introduced PRP contracts the same time.
D: Many firms in the metalworking industry have moderized production equipment in the last five years , and most of these introduced PRP contracts the same time.
问题：这个选项并没有讲现化化使生产率提高，如果有讲，那当然是他因，但D根本没讲，只是讲现代化和PRP的引进时间相同。