I know the comparison of acidic strength is asked before here and here but the first question is about the organic chemistry (and i am talking about the inorganic chemistry) and the second talks nothing about the molecules like $\ce{Cl2O7}$, $\ce{P4O10}$, $\ce{CO2}$, $\ce{N2O5}$, $\ce{Al2O3}$ etc.
These molecules are different. They do not contain the hydrogen atom. So what are the factors which affects their acidic or basic strength?
EDIT
I want to add the question (if it helps in anyway) which bring me this doubt:
Which of the following is the correct order of acidic strength?
(A) $\ce{Cl2O7}$ > $\ce{SO2}$ > $\ce{P4O10}$
(B) $\ce{CO2}$ > $\ce{N2O5}$ > $\ce{SO3}$
(C) $\ce{Na2O}$ > $\ce{MgO}$ > $\ce{Al2O3}$
(D) $\ce{K2O}$ > $\ce{CaO}$ > $\ce{MgO}$