CREATE TABLE table_81 ("Particulars and Characteristics" TEXT, "Shivalik Zone" TEXT, "Mid-Hill Zone" TEXT, "High hill zone" TEXT, "Trance- n Himalaya Zone" TEXT)

For mid-hill zone what is the altitude?
SELECT "Mid-Hill Zone" FROM table_81 WHERE "Particulars and Characteristics" = 'Altitude'
SELECT "Mid-Hill Zone" FROM "table_81" WHERE "Particulars and Characteristics" = 'Altitude'