【题目】When he was told that only a few apartments were still __________, he hurriedly took out all of his bank savings to place an order for a flat.
A.empty
B.hollow
C.convenient
D.vacant

【答案】D
【解析】句意：当他听说只有几个公寓还是空着的时候，他就赶紧拿出所有的积蓄来买一个公寓。vacant表示空着，故选D项。