about artificial snow from the text?\rA. It is still not as good as natural snow.\rB. It is made of water and ice mixed in machines.\rC. It falls into eight types depending on water content.\rD. It has been widely used in the Olympic Winter Games.\r14. What kind of snow is used in the night?\rA. Natural snow. B. No. 3 snow.\rC. Drier snow. D. Wetter snow.\r15. How do they prevent affecting the environment according to Wei Qinghua?.\rA Water from melted snow is collected and reused.\rB. Natural snow is made use of as much as possible.\rC. Underground water is pumped up for use.\rD. Snow-making is made more energy efficient.
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