Choose the correct word to complete each sentence.
1. Cars are expensive, but houses are (a) cheaper than cars/ (b) more expensive than cars.
2. Dave is 27 years old. His sister is older (a) than he is/ (b) than he does.
3. The white coat is warmer (a) then/ (b) than the gray one.
4. The food at Joe's cafe is (a) as good as/ (b) better that the food at Chez Claude,