问题补充:
The Great wall is the only one of the buildings on the earth seen from the moon.
A. which is
B. which are
C. that are
D. that is
答案:
A. which is
B. which are
C. that are
(答案→)D. that is
解析:考查定语从句。当先行词是指物的表达代词,且前面有the only/the last/the very修饰的时候,后面的句子如果使用关系代词,则使用that.本题的先行词one前面有the only修饰,定语从句中缺主语,且one是单数形式,说明后面也应该是单数,故D正确。