Looks like the Great Firewall or something like it is preventing you from completely loading www.skritter.com because it is hosted on Google App Engine, which is periodically blocked. Try instead our mirror:
This might also be caused by an internet filter, such as SafeEyes. If you have such a filter installed, try adding appspot.com to the list of allowed domains.
China's Beijing Language and Culture University has used its nearly 30 years of teaching experience to develop and write this series of textbooks. The series teaches skills in pronunciation, grammar, vocabulary, written, spoken, and listening comprehension. Thanks to zhounana for creating this list!
Hanyu Jiaocheng 汉语教程 (Chinese Language Course) Book 3, Part 2, Revised. Written by Yang Jizhou. Published in 2006 by Beijing Language and Culture University. ISBN: 9787561916728.