第36题: [单项选择]I ______ writing the paper as scheduled, but my mother's illness interfered. I hope you will excuse me. A. am to have finished B. was to have finished C. was to finish D. ought to finish 参考答案:B 答案解析:本题考查be to have done,表示事与愿违的虚拟语气。根据题意,论文是早该写好的,但是由于母亲生病耽搁了,没有完成,而且是针对过去的事情,所以用was to have finished.