Read the text below and mark the letter A, B, C or D to indicate the correct answer to tacit of the following questions from 15 to 19.

Exericse can be fun!

Exercise has become a huge part our world. There are gyms everywhere, but if you're not keen on them, there are hundreds of exercise videos to choose from. Exercise is good for you. It makes you feel better, look better and can help you live longer.

But what happens if you are the kind of person who would do anything rather than spend five minutes on an exercise bike, including cleaning the house, visiting a boring relative or watching a terrible TV programme? If you are that kind of person, you need a plan.

First of all, decide when you are going to exercise. Choose three times a week, like me. Write EXERCISE in your diary, on your calendar, on the wall if necessary! Then make sure you do it. Don t do anything else. I never make other arrangements.

Next, vary what you do. I went to the same aerobics class for two years! No wonder I was bored! Now I use different machines at the gyms, I often change my jogging route and I never do aerobics.

Make exercise fun and find an exercise you enjoy. Why not play a sport, or join a dance class? I recently started a modem dance class. It’s great fun and I’ve met lots of new people, but as soon as I get bored I’ll find something else.

What is the writer’s main aim in writing the text?