问题补充:
The boy is to go to school..
A. enough old
B. young enough
C. old enough
D. enough young
答案:
A. enough old
B. young enough
(答案→)C. old enough
D. enough young
解析: enough adj.足够的,修饰可数名词或不可数名词,可以放在名词前面,也可以放在名词后面;adv.足够地,修饰形容词、副词、动词,并放在其后。根据题意这个男孩要去上学应该是足够大,所以选C.