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未知题型 48题A.People spend more time at shopping centers that have trees.B.In hot countries, urban forests are cool places for walking and other healthy exercises.C.But you are not in rural area.D.Trees take pollution out of the airE.In 2033, it will have 5 million trees.F.It has many kinds of birds in the country

单项选择题 加涅将学习分为智慧技能等五种类型的依据是（）