After when (how much period of time of hubpages account)i can apply for Google AdSense account?

It depends on how many hubs you have and how much traffic you're getting to your hubs. In my experience 5 hubs with good quality content and about 2 weeks on HP was sufficient to get accepted. Good luck.

If you're from India or China, Google has strictly said to apply only after 6 months. But I don't think you need to wait that much. If you have unique quality textual contents, then you'll eventually be accepted if you apply after 2 months or so.

Till that time, make more followers and more quality hubs. If you're not from India or China, then wait for a month and then apply. After applying for AdSense, make a hub in between.

Google will watch your account carefully and see your potential!

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.