What Is A Perennial

Can anyone discuss to me what a perennial problem is?
my professor ask us to write 3 perennial problems in Philosophy of Man. then we have to defend in class why is it considered as a perennial problem.. could you help me please? give me 3 perennial problems in form of QUESTIONS then explain to me each why is it said to be a perennial problem..
well we are not going to do your homework for you.
You have posted in the botany section, in which we use the word perennial to describe a plant. A perennial plant is one that comes back each year.
So, a perennial problem of man is one that man has struggled with through all time, since day one. Such as why do people suffer? or, what is the reason for love?
the rest is up to you!
What is an annual compared to a perennial?