changes made:

1 alot of time to look at the original codes by Prof Hwang
2 added features of learning
15 june 2010
3 debug the problem
E:\EJS_4.3.0_100613\EJS_4.3.0\workspace\output\users\sgeducation\lookang\weexva10_pkg\weexva10View.java:739: ';' expected
   if ("d2correct ".equals(_variable)) __d2correct _canBeChanged__ = false; // Variables.basic:34
by removing the space at the back of the variables declaration, which causing compiling error
4 recompile to fit width = 600.
22 decemeber 2010
5 add picture of tree by megabanjo2017 creative commons attribution http://www.flickr.com/photos/38171671@N02/3511369490/sizes/m/in/photostream/ cartoon house by PeterBrough http://www.openclipart.org/detail/cartoon-house-by-peterbrough thanks to idea from http://standards.nctm.org/document/eexamples/chap5/5.2/index.htm#APPLET
6 created activities to support the learning