1, do not use the third variable, exchange A = 20, b = 10 these two variables?
2, the difference between several compatibility methods in VB, in the case of using that kind of compatibility? (Not compatible, engineering compatibility, binary compatibility)
3, talk about the polymorphism in VB?
4. If you write a class provider to do code sharing, but don't create an instance when you use it, what does the instance property be set?
5, type and meaning of the cursor and lock in ADO (must test)
