World markets opened to all countries, and multilateral trade flourished .
A、suffered a lot of
B、depressed sharply
C、developed quickly
D、reduced much
【正确答案】：C
【名师解析】:根据题目内容，世界市场向所有国家开放，并且多边贸易"flourished"，意味着贸易得到了快速发展和繁荣。选项C "developed quickly" 正确地反映了这种繁荣的状态，因此是正确答案。其他选项A "suffered a lot of"、B "depressed sharply" 和 D "reduced much" 都表达了负面的情况，与题目中繁荣的贸易状况不符。
