问题
选择题
With the help of high technology, many new substances（物质）______in the past years.
A．discovered
B．have discovered
C．had been discovered
D．have been discovered
答案
答案：D
考查时态语态：时间是in the past years.时态用现在完成时，new substances和discover是被动关系，句意是：随着高科技的发展，在过去的这些年里，很多新的物质被发现了。选D。