单选题 My friend was gone ______ after staying in the same house for over six months.
A. for good B. for all
C. on end D. on the spot

【正确答案】 A
【答案解析】[解析] 固定搭配
A．for good永久地，一劳永逸地；B．for all尽管；C．on end连续地；D．on the spot当场；因此A为答案。