"Compulsory" would be "Optional"? I'm learning too!
And according to Thesaurus.com, "To follow suit" which i did'nt know the meaning would be the antonym of "to be original"...
Wait, Raz, let me keep this one open, as I have to finish this english excercises book of 300 pages. I'll be needing help, and I don't wanna open multiple topics.