Write a recursive procedure that calculates and returns the factorial of a number. the number must be passed on through the stack. then write a complete program to test your procedure.

Dr. wisteria is a prominent chiropractor in the chicago area. she wants to provide a forum for her patients to discuss their health concerns and to seek and offer advice to other patients. which telecommunications tool is most appropriate for dr. wisteria's needs?

Write lines of verse that rhyme to remember the following information: acid rain is a type of air pollution caused by chemicals in the air.

Write a method named addall that could be placed inside the hashintset class. this method accepts another hashintset as a parameter and adds all elements from that set into the current set, if they are not already present. for example, if a set s1 contains [1, 2, 3] and another set s2 contains [1, 7, 3, 9], the call of s1.addall(s2); would change s1 to store [1, 2, 3, 7, 9] in some order. you are allowed to call methods on your set and/or the other set. do not modify the set passed in. this method should run in o(n) time where n is the number of elements in the parameter set passed in.