Answer:
I don't have a Apple, but I suggest you either contact Apple Help, or go to settings and see if you can reset it.
Add-on:
I hope this helped you at all.
An Object Class. Hopefully this answer is right.
Answer:
See the constructed 12-bit adder/subtractor from the components below
Explanation:
A) operating system
It is going to let you "operate" it using the mouse and keyboard