1有夢魘，2 個體差別大,  3. 有待探索.
By the way, my coming book will tell the secret of 
why "I am, he is, you are, we/they are" not "he/you/we am.....",
*ask the native speakers, see anyone can answer.

http://www.wenxuecity.com/news/2013/11/21/2804747.html

成就成功  Traci Reedy 典型的危險名字