Ex. A page. 42

1. I don’t believe you. It can’t  be true.
2. He should consult a doctor before he goes on a diet.
3. Could you open the window, please?
4. I can climb that wall. It isn’t very high.
5. You can keep yourself fit by walking a certain distance every day.
6. You have to be at the airport two hours before your flight. Don’t be late.

Ex. B page. 42

1. You should go to the dentist.
2. My family can’t be at home.
3. He may not come.
4. You don’t have to take any warm clothes with you.
5. Will you close the window, please?
6. Can I help you?

Ex. C page. 43

1. She can’t have won the prize.
2. She may have lost her keys.
3. They must have rented a house in the suburbs.
4. She didn’t have to do the laundry.
5. You should have packed.
6. He may have overslept.

Ex. D page. 43

1. You oughtn’t to have been late.
2. She had to paint the gate yesterday.
3. They speak Japanese very well. They must have lived in Japan in the past.
4. She didn’t have to do the dishes.
5. I had left my keys in the house but I was able to get in through the window.
6. Gloria needn’t have cleaned the house but she has already done it.
7. They could have crashed into the wall. But luckily the driver braked hard at the last minute.

Ex. E page. 43

Nowadays, as soon as a fast food restaurant opens, it has to advertise its specialties to appeal to people’s eating preferences. If it manages to attract consumers’ interest quickly then it must increase production to meet consumers’ demands; this means that this business has all the prospects to become a profitable one.

Today, it is well-known that fast food is teenagers’ favourite food, so if parents happen to very busy and they cannot prepare a meal, a fast food restaurant might solve their problem. Therefore, they needn’t worry about what their families’ meals have to be. However, it should be noted that some years ago, a great number of people used to consume  great amounts of fast food every day but now things have started to change. They are making an effort to reduce it as much as they can, because dieticians and nutritionists claim that we should prefer home-made and traditional dishes if we want to be healthy.