分解因式：4x³﹣4x²y+xy²=____ ．

现实世界空间是三维的，绘画作为平面艺术是二维的。画家在二维平面所画的，只能是三维现实空间中实际物体的一部分，而人脑则通过这个部分将其想象成完整情形。由此可见（    ）

①艺术创作活动具有主动创造性      ②艺术的内容根源于创作者的构思

③人脑为艺术创作奠定生理基础      ④意识与之反映的实物必然存在差异

    Mary is an African elephant. Now she is 16 years old.She lives in the zoo. Mary has produced more than 50 drawings since last year. She has made over $2,500 for the zoo. Zoo leaders said Mary first showed the art ability (能力) about 4 years ago. Zoo workers watched her make the marks (痕迹) in the sand with her trunk (象鼻). She rubbed out (抹去) the marks, then made the new ones. The zoo workers gave her brushes and paints. Soon Mary was drawing pictures. Newspaper reporters wrote about Mary, and then people went to buy her pictures. And in this way she made a lot of money for the zoo by drawing.

    This is how Mary does the drawing.A zoo worker holds different color paints and Mary touches the colors she wants. Then the worker gives her chosen color to the brushes in her trunk and Mary begins to paint.

哈大客运专线(哈大高铁)于2012年7月正式通车，它大大缩短了哈尔滨到大连的客运时间。下图为哈大客运专线示意图，据图回答下列各题。