Modal Verbs(Possibility/Certainty/Deductions); Question Tags

Which sentence would you use in the following situations?

You`re approaching your friend`s house.You can see lights on in two rooms.

Which sentence would you use in the following situations?

You have to revise a lot before your exam on Monday.

Which sentence would you use in the following situations?

You don`t believe your friend`s story.

Which sentence would you use in the following situations?

Your friend from school has been very sad recently.

Which sentence would you use in the following situations?

You have some doubts if changing your present job is a good idea.

Which sentence would you use in the following situations?

You can see a small boy trip over a ball and sprain his ankle.

Don`t worry! He _______________ the tickets for us. I saw him buying them.

You ____________ a lot before you gave your speech.It was really good.

Amanda _________ her work, but she felt ill and had to go home.

Why is that man looking around like that? He_________be lost.

I don't know why he did not perform well in the concert. He _________ practice.

He __________the crime, as he had both the motive and the opportunity.