单选题 If something very substantial is not done next month, he cannot ______ his office.
【正确答案】 D
【答案解析】[解析] 动词词义辨析。根据句中If...is not done...，he cannot...双重否定表达，判定此处的意思是“保住职位”。选项中，只有retain符合句意。故答案为D。