第20题: [单项选择]The parents thought that their only child was not yet ______ to be independent. A. enough old B. so old C. old enough D. too old 参考答案:C 答案解析:enough作副词用时通常要放在所修饰的形容词或副词的后面。因此,选项A是错误的。选项B需要在后面加上as才能够成为正确的选项。选项D的意思不对,因为too...to...表示的是“太……以致不能……