Give examples of mountains and plains of different heights.

Different plains and mountain systems are located at different heights from sea level. For comparison, one can bring as an example the Uldza-Torey plain in the east of Russia. This plain with a height of 500-700 is considered high-altitude. A second example is the Anatolian Plain, which is classified as a plateau with an altitude of 800-1500 meters.
There are Caucasian mountains in the south of Russia up to 6 thousand meters. Their average height is 3-4 thousand meters, take off you can compare Kara-Korum, which has an altitude of more than 8000 meters above sea level.