Professor James will give us a lecture on the Western culture,but when and where( ) yet.
问题描述：
Professor James will give us a lecture on the Western culture,but when and where( ) yet.
A.has not been decided B.have not decided
C.is not being decided D.are not decided
什么是投射定理?
答
when and where has not been decided.选A.表示时间地点还没有被定好.因为是被动语态,所以用been decided.而when and where这表示时间地点一个整体,用单数形式.用has.故选A.