问题补充:
The parents are their son who has been away from home for days.
A. in search of
B. to search
C. searching
D. searched for
答案:
(答案→)A. in search of
B. to search
C. searching
D. searched for
解析:考查句子结构。句意:这对父母正在寻找他们已经离家几天的儿子。不定式表示具体的将要进行的动作,选项B不符语义。Search表示寻找某物后面一般要加介词,根据语境可知本句也不是被动语态,故用短语in search of,选A。