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.
This is an intermediate-level course in written Chinese that employs a revolutionary new method designed to have you quickly reading and writing simple, connected Chinese sentences.
By Cornelius C. Kubler, published by Tuttle Publishing, 2015. ISBN-13: 978-0804840200