The new teaching building before the new term begins.
A. must be finished
B. must finish
C. must finished
D. must being finished
网友回答
(答案→)A. must be finished
B. must finish
C. must finished
D. must being finished
解析：句意：新的教学大楼必须在新学期开始前完工。结合语境可知本句主语为动作对象，故用被动语态，选A。