【正确答案】[参考译文] Although our understanding of learning is still not complete，a great deal is known．Learning has many different forms and takes place under many conditions．In gener al，it involves a change in behavior．When a change in behavior takes place as a result of learning，the change is usually a long-lasting one．Learning may mean that a number of small independent acts are arranged in a new order．This happens，for example，when you learn to play a new piece on the piano．