Ответы и объяснения

3. The chair is as high as the bench.
4. The girl is as tall as the boy.
5. The green tree is not as tall as the brown tree.
6. The sitting-room is not as cosy as the bedroom.
7. The kitchen is as clean as the hall.
8. The garden is as green as the forest.
(1 и 2 сделаны в примерах, если что)