If you (a)   (cool) water at 0o C , it freezes.

If you water a cactus everyday , it (a)   (die) in a short time.

A bee (a)   (sting) you, if you touch it with bare hands.

If you go to the north pole, you (a)   (get) a cold.

If you leave margarine under the sun, it (a)   (melt) in a very short time.

If I (a)   (add) lemon juice to the salad, it tastes sour.

If we (a)   (look) at the computer screen for a long time, we have some eye problems.

If a dog (a)   (wave) its tail repeatedly, it likes you or wants food from you.

If you eat a lot of ice-cream ,you (a)   (get) overweight.

If you pull a dogs tail and hurt it, it (a)   (bite) you immediately.

If it (a)   (not rain) for a long time, the plants fade and dry.

If you get enough sleep every day, your skin (a)   (look) well and healthy.

If you brush your teeth regularly, they (a)   (look) white and healthy.

If you (a)   (mix) gold and silver, you get a green metal.