Sure! Here are the combined sentences using (not) as ... as:

1. John is 1 metre 80 cm tall. Dave is 1 metre 80 cm tall.
→ John is as tall as Dave.

2. Seville has temperatures of 40°C. Cordova has temperatures of 40°C.
→ Seville is as hot as Cordova.

3. John is not very clever. Mary is cleverer.
→ John is not as clever as Mary.

4. The blue car is not expensive. The red car is more expensive.
→ The blue car is not as expensive as the red car.

5. Mrs Jones talks very quietly. Mrs Smith talks more loudly.
→ Mrs Jones does not talk as loudly as Mrs Smith.

6. The brown house is 100 years old. The greenhouse is 100 years old.
→ The brown house is as old as the greenhouse.

7. Steve did not do well in the English test. Melissa did better in the English test.
→ Steve did not do as well as Melissa in the English test.

8. The Impala runs 90 km per hour. The cheetah runs 120 km per hour.
→ The Impala does not run as fast as the cheetah.

9. The first exam was difficult. The second exam was difficult too.
→ The first exam was as difficult as the second exam.

10. Ciudad Real is not very beautiful. Seville is more beautiful.
→ Ciudad Real is not as beautiful as Seville.

11. My salary is high, but yours is higher.
→ My salary is not as high as yours.

12. You know a bit about cars, but I know more.
→ You do not know as much about cars as I do.

13. It is still cold, but it was colder yesterday.
→ It is not as cold as it was yesterday.

14. I still feel a bit tired, but I felt more tired yesterday.
→ I do not feel as tired as I felt yesterday.

15. Mary and Kate are kind.
→ Mary is as kind as Kate.