With the help of high technology, more and more new substances in the past few years.
A. discovered
B. have discovered
C. had been discovered
D. have been discovered
网友回答
A. discovered
B. have discovered
C. had been discovered
(答案→)D. have been discovered
解析：考查时态。根据时间状语in the past few years,说明使用现在完成时。根据句意说明使用被动形式。句意：因为有高科技的帮助，早最近几年中，越来越多的物质已经被发现了。故D正确。