Which of the following statements is true?
a) when you drive a car, pressing its gas pedal sends a message to the car to perform a task—that is, to go faster.
b) you send messages to an object; each message is implemented as a method call that tells a method of the object to perform its task.
c) a program might call a bank-account object's deposit method to increase the account's balance.
d) all of these statements are true.

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.

Ulia is planning to attend the same private four-year college her parents attended. she wants to save at least $18,000 in four years to contribute to her college education. which monthly deposit amounts can julia use to achieve her goal? check all that apply.

Which network media uses different regions of the electromagnetic spectrum to transmit signals through air? uses different regions of the electromagnetic spectrum to transmit signals through air.