1 - c

2 - f

3 - a

4 - e

5 - b

6 - d

1. If you study hard, you'll pass all your exams.

You'll pass all your exams if you study hard.

2. If the weather is bad, we'll not have a barbecue.

We'll not have a barbecue if the weather is bad.

3. If you don't listen to the instructions, you'll not know what to do.

You'll not know what to do if you don't listen to the instructions.

4. If she doesn't invite Joe to her party, he'll be upset.

He'll be upset if she doesn't invite Joe.

5. If we don't leave now, we'll miss the train.

We'll miss the train if we don't leave now.

6. I'll watch it if match be on TV.