17.Paper money was in __ use in China when Marco Polo visited the country in__ thirteenth century.A.the;\ B.the;theC.\;the D.\;\为什么要用C

17.Paper money was in __ use in China when Marco Polo visited the country in__ thirteenth century.
A.the;\ B.the;the
C.\;the D.\;\
为什么要用C

选 C.\;the
因为：in use 是惯用法,而thirteen century 前必须加定冠词the：the thirteenth century 十三世纪