Since we are comparing let's convert everything to the same units...
70 inches = 70 inches
5 1/2 feet ..12 inches per ft
5.5 × 12 = 66 inches
2 yards.. 3 ft per yard
2×3 = 6 ft.. 12 inches per ft
6 × 12 = 72 inches
So from least to greatest...
5 1/2 ft; 70 inches; 2 yards