The Respiratory System

The left main ________ is smaller in caliber but longer than the right, entering the root of the left lung opposite the sixth thoracic vertebra.

One 1 2 3 4 5 6 7 8 9 10 11 12
Two 13 14 15 16 17 18 19 20
Three 21 22 23 24 25 26 27 28
Four 29 30 31 32 33 34 35 36 37
  
Physics
Chemistry
Organic Chemistry
Biology