20 how do you figure this out and what's the answer

Tanya was used to using word, and she did some work for her brother mike, who was using wordperfect. tanya was quickly able to use wordperfect for windows with little difficulty, since many of the commands for it were the same as the commands for word. tanya's ability to use wordperfect best illustrates:

What greek scientist created a screw to move water for irrigation?

Who is the current chief justice of the united states?