Open the brackets using as…as
1 He (tall) Sara.
2 I (not strong) Tim.
3 Your hotel (not expensive) ours.
4 My dog (not young) my cat.
5 He (slow) as turtle.
6 The flats (comfortable) the houses.

He's as thin as SaraI'm not as strong as TimYour hotel is not as expensive as oursMy dog ​​is not as young as my catHe’s as slow as turtleFlats are as comfortable as houses.