一道英语题，请详细解答，谢谢。在线等

答案C

be prepared for: 为....做准备

完整的句子应该是这样的:Susan worked late into the night,to be prepared for the exam next week.

Susan为了下星期的考试,学习到深夜.后面是不定式短语做目的状语.省略to be后,选C

为什么楼上这么多人说be prepared for？ 难道prepare for sth.不行么？
我个人认为是B.preparing.
理由：preparing for the exam next week做伴随状语。而且就算是是用to be prepared for的结构的话，也应该是不要逗号的。所以我认为c是错的。Determined to catch up with other students,he studies very hard.这句可以还原成“When he is determined to catch up with other students,he studies very hard.”请问这句话怎么还原？我认为还原不了。

希望楼上的可以继续阐明你们的理由。

选择C答案，因为本身有be prepared for这个结构，这里是过去分词做状语，当省略引到的关系代词时，把主语和谓语一起省略，剩下的就只有prepared 了

选c 固定短语be prepared for sth:ready to do sth or deal with a situation.
be prepared for the exam 在此直接去掉be后即可作为状语。

英语里面有很多（固定短语去掉be后充当状语）相类似的例子：Lost in the forest,he was missing his family.(be lost in)

Determined to catch up with other students,he studies very hard.

选b
ing用于人 表示主动 ed用语物表示被动