问题补充:
Upon arriving home, I was surprised to find the paper I had had was missing.
A. to be prepared
B. to prepare
C. preparing
D. prepared
答案:
A. to be prepared
B. to prepare
C. preparing
(答案→)D. prepared
解析:考查have sth done“请人做,使…被做”词组,分析句子the paper后面是定语从句,两个had,一个是助动词,一个是使役动词,在定语从句中从当宾语的关系代词被省略,prepare和the paper是被动关系,选D,意为:一到家,我很惊讶的发现我准备好的文件不见了。