Ответ:

1)

1. Faster
2. Older
3. Cheaper
4. More expensive
5. Hotter
6. Better
7. Happier
8. More beautiful
9. Safer

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2)

1. A motorbike is faster than a bicycle.
2. She is taller than him.
3. A red bike is more expensive than a blue bike.
4. Her book is more interesting than his book.

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3)

1. Karen is younger than Tom, Tom is older than Karen.
2. The Mississippi river is shorter than the Amazon river, The Amazon river is longer than the Mississippi river.
3. My flat is smaller than your house, your house is bigger than my flat.
4. Today the temperature in Rome is higher than in London, today the temperature in London is lower than in Rome.