| Answer | Crossword Clue |
|---|---|
| ALT | No. of ft. above sea level |
| ELEV | Ft. above sea level |
| ALT | Ft. above sea level |
| ALT | Ft. above sea level, to a pilot |
| ecosphere | the part of the atmosphere in which it is possible to breathe normally without aid: the portion of the troposphere from sea level to an altitude of about 13,000 ft. (4000 m) |
| CASPIAN | Sea, 92 ft. below ocean level. |
