at the Isthmus of Panama, so animals were able to migrate between North and South America. A. With a land bridge B. When a land bridge existed C. A land bridge D. A land bridge exi
___________ at the Isthmus of Panama, so animals were able to migrate between North and South America.
A. With a land bridge
B. When a land bridge existed
C. A land bridge
D. A land bridge existed