Mao Kun map is often seen as a surviving document from the expeditions of the mariner whose ships could stretch past what length?
Mao Kun map:  The map is often regarded as a surviving document from the expeditions of Zheng He in addition to accounts written by Zheng's officers, such as "Yingyai Shenglan" by Ma Huan, "Xingcha Shenglan" by Fei Xin, and "Xiyang Fanguo Zhi" by Gong Zhen. Zheng He: Zheng He (1371–1433 or 1435), formerly romanized as Cheng Ho, was a Hui Chinese mariner, explorer, diplomat, fleet admiral, and court eunuch during China's early Ming dynasty.
i don't know