The period when the great painted caves at Lascaux and Altamia were occupied by Upper Paleolithic people has been established by carbon-14 dating ,but what is much more difficlt to determine are the reason for their decoration。。。。 请问是what引导的一个从句在but----decoration这句话里充当主语吗?如果是,这个从句相应的主句又是什么呢?谢谢~ -- by 会员 xyc19901015 (2011/2/17 14:05:24)
the reason for their decoration are much more difficult to determine, what 指后面的 the reason .... |