问题补充:
When , the new railway will run for 250 miles.
A. to complete
B. completed
C. being completed
D. to be completed
答案:
A. to complete
(答案→)B. completed
C. being completed
D. to be completed
解析:考查非谓语动词。句中的逻辑主语the new railway与complete之间为被动关系,故用过去分词作状语。句意:当新铁路完成的时候,铁路的运行长度将达250里。故B正确。