单项选择题 根据参与者的介入程度和品牌间的差异程度，协调型购买行为的基本特点是( )。

单项选择题 Lily is a good student except()she is a little bit careless.A. whereB. whichC. that

单项选择题 the better the elderly people are known,()they are.A. the happierB. the happyC. so happy