Choose the correct option

1. Wear sunscreen
   [if | unless] it's sunny outside.
2. We will go sailing
   [if | unless] the wind is too strong.
3. You will get wet immediately
   [if | unless] you wear some waterproof clothes.
4. I would let you drive the car
   [if | unless] you were so irresponsible.
5. I would help you
   [if | unless] I could.
6. [If | Unless] you were quiet, I could concentrate on reading.
7. He could be a better runner
   [if | unless] he trained harder.
8. We would have come here earlier
   [if | unless] we had stopped to have some ice cream.