All through development, observatories have been included in the layout of Machu Picchu. Stonemasons formed these structures to observe the movements of celestial beings. This ingenious society noticed that astronomical know-how was essential for improved agricultural output. 比如，如果选择对“图书馆在非物质文化保护中的作用”进行综述，可以先收集与非物质文化有关的一些文献，如《非物资文化... https://louisqsfyi.tusblogos.com/11650669/文献综述代写-no-further-a-mystery