The term "4,000米" refers to a height of 4,000 meters, which is approximately 13,123 feet. This elevation is significant in various contexts, such as mountain climbing and aviation. For instance, many of the world's tallest mountains, including those in the Himalayas and Andes, reach or exceed this height. At 4,000 meters, the atmosphere becomes thinner, leading to lower oxygen levels. This can affect human physiology, making it challenging for unacclimatized individuals to breathe. Activities like mountaineering often require climbers to adapt to these conditions to prevent altitude sickness.