Which labels best complete the diagram? X: Two-chambered heart
Y: Swim bladder
X: Single-chambered heart
Y: Swim bladder
X: Gills
Y: Lateral line
X: Lungs
Y: Lateral line

Which option best completes the diagram? the cold war is the major u.s. foreign policy priority terrorism becomes a major concern of u.s. foreign policy. a. the second iraq war begins. b. the september 11 terrorist attacks occur. c. terrorists attack the 1972 summer olympics. o d. the soviet union collapses.