What is Arrivederci Mean ? ? ?

Hello, i need you to me my teacher sent me a letter to the reader and in the letter i have to put in. why do i want to get 3 points? and he said that of the 4 arguments choose one and that with that argument write the letter these are the arguments: addition: also that, even that, too. comparison: more than, less than, as much as. opposition: but, however. security: without a doubt, of course. those are the 4 arguments and i have to choose just one, i need it it's very urgent you it's about language and literature

Which sentence uses the verbs correctly?

What is the longest word in the world? this is grammar.