PART III-Write T if the statement is TRUE, and F if it is FALSE. Write your answer on the space provided before the number. Take 21. Satellites burn up in the mesosphere. Fac 22. The exosphere is the lower limit of our atmosphere. 23. The stratosphere starts just above the troposphere and extends to 50 kilometers (31 miles) high. 24. Earths atmosphere has three major and several secondary layers. 25. A greenhouse is a building with paper walls and a paper roof.