【单选题】5 The 27 member EU negotiates trade agreements as one. The EU and Brazil have negotiated a strategic trade alliance which is an example of a ________.
【单选题】当两种不同旅游产品是一种替代关系时,其旅游需求交叉弹性系数特征是( ) When two different tourism products are a substitute relationship, the cross elasticity coefficient ( 交叉弹性系数 )of tourism demand will be ( )