List the six external parts or peripherals of a computer system

When you collaborate or meet with a person or group online, it is called

Create a cell reference in a formula by typing in the cell name or         a. right-clicking the cell. b. clicking the cell. c. clicking the column where the cell is located. d. clicking the row where the cell is located.

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.