Nowhere in nature is aluminium（铝）found free, owing to its always ______ with other elements, most monly with oxygen.
A.bined
B.having bined
C.bine
D.being bined
网友回答
A解析owing to为介词短语，后接v.-ing短语作宾语，bine与名词aluminium是被动关系，故用被动形式being bined表示“正在被联合”，显然本题无此语境。B、C两项因为是主动形式，也不符合本题语态要求。