If you want to study the Solar System,

• you had to use telescopes.

• you has to use telescopes.

• you have to use telescopes.

• you are having to use telescopes.

If you have an accident,

• you must go to the hospital.

• you had to go to the hospital.

• you would go to the hospital.

• you could go to the hospital.

If you have a pair of binoculars,

• you can see the birds clearly.

• you could see the birds clearly.

• you would see the birds clearly.

• you might see the birds clearly.

If you don't eat,

• you got angry.

• you have gotten angry.

• you get angry.

• you are getting angry.

If students study hard,

• teachers were always happy.

• teachers are always happy.

• teachers will always be happy.

• teachers would be always happy.

If the weather is fine,

• I walk to school.

• I walked to school.

• I am walking to school.

• I was walking to school.

If you don't sleep,

• you could get tired.

• you would get tired.

• you get tired.

• you had gotten tired.

If you add two and two,

• you get four.

• you got four.

• you are getting four.

• you had gotten four.

If you are in the library,

• you should be quiet.

• you would be quiet.

• you could be quiet.

• you might be quiet.

If you ______ to get a good grade, you _____ to study hard.

• wanted / had

• have wanted / have had

• want / have

• would want / would have