The common noun here is "frog" as the only other noun, Many, is not a common noun - it's a proper noun.
"frog" here is the object of the sentence: it's the object of the verb "caught" of which the subject is Mary
For he thinks that this kind of friendship can exist only when one spends a great deal of time with the other person, participating in joint activities and engaging in mutually beneficial behavior; and one cannot cooperate on these close terms with every member of the political community.
to improve intelligence first the person wants to make people intelligent must be literate and if the people are literate it can be very great because literation leads toward victory and if the people of country are literate the country will be rich because everyone knows where to invest and where to spend money
