[ 151 ] Earth and Space Science GED ® TEST SCIENCE FLASH REVIEW • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 520 km 500 km 490 km –10 –50 0 50 100 150 200 500/1,500 Temperature ºC Troposphere Stratosphere Mesosphere Thermosphere Exosphere Altitude 160 km 140 km 120 km 100 km 80 km 60 km 40 km 20 km The troposphere is the lowest portion of Earth’s atmosphere. What percentages of the atmosphere’s mass, water vapor, and aerosols do you think it contains, respectively? A. 50%, 32%, 40% B. 70%, 60%, 77% C. 80%, 99%, 99% D. 75%, 65%, 65%