How often does satellite picture on google earth gets refreshed?

It depends, some areas like war zones, for obvious reasons. Other places that are updated more frequently are popular tourist destinations and larger cities, Seattle will be updated more frequently than say Alma ,Ga. Google earth also points to a hidden feature allowing you to bring up the current view in Google maps,if you choose the "link to this page" option in Google maps after searching for a location, you can bring up the current view in Google earth by appending "&output=kml" to the URL.

No one answered you sooner because you put this question in education, instead of Google. More.

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.