1 Down syndrome, usually is caused by an extra copy of chromosome 21 (trisomy 21). Characteristics include decreased muscle tone, asymmetrical skull, slanting eyes and mild to moderate mental retardation.  Edward's syndrome, which is the second most common trisomy after Down syndrome. It is a trisomy of chromosome 18.
Guanxi describes the basic dynamic in personalized networks of influence, and is a central idea in Chinese society.
Chinese (æ±è¯­/æ¼¢èª; HÃ nyÇ or ä¸­æ; ZhÅngwÃ©n) is a group of related, but in many cases mutually unintelligible, language varieties, forming a branch of the Sino-Tibetan language family. Chinese is spoken by the Han majority and many other ethnic groups in China.