Top 7. Because there is culture difference.
One of the main reasons Chinese is so difficult for westerners is that the culture between the East and the West has been isolated for so long. China has had extensive contact with the West in the last few decades, but there is still a vast sea of knowledge and ideas that is not shared by both cultures. When westerners and Chinese get together, there is often not just a language barrier, but an immense cultural barrier as well.

原因七：存在文化差異。
東方、西方相互之間文化分隔的時間太長，這也是漢語對于西方人來說為何那么難學的主要原因。盡管在過去幾十年里中國和西方之間有了廣泛的接觸，然而，中國人的知識和思想浩瀚如海，西方人卻無緣享用。即使有朝一日西方人想和中國人融合成一體，其障礙往往也并非只是語言一個方面而已，最大的障礙是巨大的文化差異。