标题: 求教prep语法一道 关于动词的单复数 ^_^ [打印本页] 作者: gete999 时间: 2010-10-27 10:16 标题: 求教prep语法一道 关于动词的单复数 ^_^ The period when the great painted caves at Lascaux and Altamira were occupied by Upper Paleolithic peoples has been established by carbon dating, but what is much more difficult to determine are the use to which primitive peoples put the caves, the reason for their decoration, and the meaning of the magnificently depicted animals.
A.has been established by carbon dating, but what is much more difficult to determine are
B.have been established by carbon dating, but what is much more difficult to determine are
C.have been established by carbon dating, but that which is much more difficult to determine is
D.has been established by carbon dating, but what is much more difficult to determine is E.are established by carbon dating, but that which is much more difficult to determine is
答案就是选D，我误选了A，不太懂后面这个are的由来，如果是根据the use... the reason... the meaning...呃，不懂。作者: xiaowei0804 时间: 2010-10-27 10:40
what is much more difficult to determine为一个主语。