求助 新prep sc2---166

emilyly

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


答案选D。 我选A。
请问is或者是are 不是应该由后面的 the use, the reason, and the meaning 来决定吗？
和what is much more difficult 中的is 有关系吗？

wzwkb

but 后面就是这一个名词性从句what is much more difficult作主语的句子  what引导的名词性从句作主语时what当中有is 主句谓语就用is

emilyly

那请问楼上如果没有is， 比如说是 what implys us 也是加is吗？就是跟着

what后面的动词单复数一样吗？

napoleon

what 这里就是 the use 所以用is

emilyly

LS这里the use, the reason, and the meaning 是并列啊。不是只有一个USE

emilyly

还是不明白，谁能帮我再解释一下啊？

minigreen

我的想法和LZ一样啊！！各种不明白。。 求NN解答！