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.
The Boya Chinese series is a textbook series comprised of 9 books and broken up into four levels: elementary, pre-intermediate, intermediate and advanced. This is the second of the two elementary level books. Between the first two books there are 50 lessons for beginners and about 1,000 words. Finishing elementary levels 1 and 2 will ensure that students reach level 3 of HSK.
Boya Chinese 博雅汉语: Elementary Starter II. Written by Li Xiaoqi.
Published in 2004 by Peking University Press. 215 pages.