单选题 I would have written before, but I ______ ill.
A. have been B. would been C. had been D. were

【正确答案】 A

【答案解析】[解析] 本题考点为虚拟语气。与过去事实相反的虚拟语气，从句用过去时，主句中用would/should/could+have done。But后面为过去的真实情况的陈述，所以用A。当时生病，现在还没有恢复。句中因为没有明显的时间对照，所以选择过去完成时。C选项had been不适合。