看几个例子:
afactorybuiltin1980=afactorywhichwasbuiltin1980(可不能用is哟)
afactorybuiltbythem=afactorywhichwas(也可能是whichhasbeenbuilt)bythem
amapshowingwherethevillageis=amapwhichshowswherethevillageis(没用isshowing哟)
amaphangingonthewall=amapwhichishangingonthewall
从上例可看出,不可机械地去套用什么形式.这还得要时态这方面的基础