thinking ,practice，and if you have some trouble in understanding something ,you can look up correlative information from all that you can find ,such as reference book,Internet.then ask somebody.
Practice is most important,though you can understand the code well,you not always can write it by
yourself.so...
^_^

Yeah,you are right.
Next time ,I will practice more by myself,and also look up more correlative informations.

Because edition owner want to flash his English away