问题补充：
When，the wholesale vegetable market will be the largest one in China.
A. completing
B. completed
C. being completed
D. to be completed
答案：
A. completing
(答案→)B. completed
C. being completed
D. to be completed
解析：考查非谓语动词。主句的主语与complete之间是被动关系，故用过去分词，做时间状语。
