unless/if

You should not swim in the river ___ you are a good swimmer.

• unless

• if

I will take a day off ___ my boss says that it is okay.

• unless

• if

You __________ improve your English unless you read a lot.

• can

• can't

She will be angry with him if he ___ sorry.

• says

• doesn't say

The rock concert ___ good unless you ___ loud music.

• will be, mind

• will be, don't mind

• won't be, don't mind

• won't be, mind

My dog ____ at you if you ____ too close.

• barks, will not get

• does not bark, will not get

• will bark, do not get

• will not bark, do not get