英语高手请进,Quite a few people used to believe that disaster ___if a mirror was broken.

题目

英语高手请进,Quite a few people used to believe that disaster ___if a mirror was broken.
A.was sure of striking
B.was sure of having struck
D.was sure to strike
可书上两句型都有：be sure /certain of sth
be sure /certain to do sth
还有书上说be sure 的主语只能是人,
但有人又细说be sure of的主语只能是人.be sure to do主语可是物也可是人,这说法对吗?
希望大家根据我问的回答啊 不要粘其他的过来 百度的解释我都看遍了还不明白才问的 感激不尽

答案

那你就抛开你在百度看的,只去了解我给出的解释就好了.
disaster is sure to strike if the mirror was broken.
你可以从这个句子看出,disaster是做主语,并且是主动句的.
过去很少人相信镜子破了,灾难就会降临.