【正确答案】Karez, a kind of water conservancy system in the droughty area of Xinjiang, is formed with wells connected by underground channels. This system collects lots of rainwater and snowmelt seeping into the ground in spring and summer and drains it to the ground surface through the natural slope of the mountain to irrigate the farmland and meet people’ s daily needs. Karez reduces the evaporation of water on the ground surface with minimal damage to it, thus effectively protecting the natural resources and ecological environment. It embodies the wisdom of the Chinese people to coexist in harmony with nature and is a great contribution to the human civilization.