Question

Rewrite the sentence using 'unless':
If you cannot keep quiet in the class, you will have to go out.
(1) Unless you keep quiet, go out
(2) Unless you keep quiet, you will have to go out
(3) Keep quiet, unless you go out
(4) Unless you go out, you will not keep quiet

Answer 1

3rd is right .
keep quiet, unless you go out .

Answer 2

The answer would be: (3) Keep quiet, unless you go out