问题
选择题
Don’t let the child who is ________ go to school．
A．so young as to
B．not old enough to
C．not old enough
D．too young to
答案
答案：C
这题考查定语从句：who is old enough是定语从句，修饰the child，而谓语let后面接宾语+省略to的不定式。选C。句意是：别让年龄不够的孩子上学。