【题目】When _______, the new stadium（体育馆） will hold 50000 people.
A. completed B. be completed
C. completing D. having completed
在线课程【答案】A
【解析】
考查过去分词作时间状语。句意：新的体育馆落成时，将能容纳五万观众。when completed=when it (=the new statium) is completed, 此处是省略，when加过去分词作时间状语，故选A。