A. counteract the effect of gravity
B. lift the bird so that it can remain airborne
C. enable the pectoral ,muscles to contract easily
D. change the direction of the flying bird
Correct Answer: Option A
A. counteract the effect of gravity
A. counteract the effect of gravity
B. lift the bird so that it can remain airborne
C. enable the pectoral ,muscles to contract easily
D. change the direction of the flying bird
Correct Answer: Option A
A. counteract the effect of gravity
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