题目

His father has promised drive after drinking any longer in the future.A.not to B.to not C.not D.don’t 答案：【答案】A【解析】句意：他父亲已答应今后不再酒后驾车。考查动词不定式。promise (not) to do sth.为固定短语，意为“承诺（不）做某事”，to do的否定式是to前加not，即not to，故应选A。设函数f（x）=ax3-3x2，（a∈R），且x=2是y=f（x）的极值点．（Ⅰ）求实数a的值，并求函数的单调区间；（Ⅱ）求函数g（x）=ex•f（x）的单调区间．