Select all the correct answers. Which four of the following are true about fair use?
involves use of copyrighted material without the owner's permission
QU
is exempted from copyright laws
depends on the character of use of the copyrighted material
O
does not require attribution
depends on the purpose of use of the copyrighted material

Explain briefly why you cannot expect to find a previous version of every file with which you work.

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.

Mariah was working on a multimedia presentation that included both video and audio files. the file was huge, and she wanted to send it to her coworker in another office. she needed to reduce the size of the file so that it could be transmitted faster. the utility she used to do this was