---Where has Mary been? I haven't seen her all day?---Oh,in order not to be disturbed, she spent the whole day __in the study, ___ her report.A.locking;preparingB.locked; preparedC.locked; preparingD.locking; prepared
网友回答
C解析此题第二空根据spend …(in) doing sth.结构应选preparing；第一空根据主语she与lock是被动关系，用过去分词作伴随状语。