Write a PL/SQL block to find the population of a given country in the countries table. Display a message indicating whether the population is greater than or less than 1 billion (1,000,000,000). Supply the missing elements in order to satisfy the above statement. 2.) Modify the code given in \#1 so that it handles all the following cases: - Population is greater than 1 billion. - Population is greater than 0 . - Population is 0. - Population is null. (Display: No data for this country.) Assumptions: - Variable vpop has been properly declared at the declaration section. - Implicit cursor has been created to store a value to vpop. Write a PL/SQL block to find the number of airports from the countries table for a supplied country_name. Based on this number, display a customized message as follows: Supply the missing elements of the given below to satisfy the above statement. nd