They are anxious that all the difficulties must______.

They are anxious that all the difficulties must______.
A、be faced up to
B、face up to
C、be facing up to
D、have been faced up to
【正确答案】：A
【题目解析】：动词+助词+介词结构的动词短语包括do away with， face up to， live up to，look down on/upon， look forward to， look out for， look up to，play around with， put up with，talk down to等需作为整体用于被动语态。