Migration, in biology, is the movement of animals to a place that offers better living conditions. Many birds, fishes, insects, and mammals regularly migrate to (16) unfavorable changes in weather or food supply.
Migrations take place on land, in water, or in the air. Some animals migrate only short (17) . Other migrations cover thousands of miles or kilometers.
Migration enables many animals to (18) favorable weather and abundant food supplies in areas with changing (19) . In some parts of the world, for example, food is plentiful in summer but becomes (20) during the cold winter months. Many animals that live in these regions migrate to (21) climates in the fall. They return in the spring when the weather warms up.
Many migrations are (22) reproduction. Numerous animals migrate to breeding areas so that their young have the best chance for (23) . Migratory birds breed in their summer ho
A. periods
B. spans
C. distances
D. lengths
Migration, in biology, is the movement of animals to a place that offers better living conditions. Many birds, fishes, insects, and mammals regularly migrate to (16) unfavorable changes in weather or food supply.
Migrations take place on land, in water, or in the air. Some animals migrate only short (17) . Other migrations cover thousands of miles or kilometers.
Migration enables many animals to (18) favorable weather and abundant food supplies in areas with changing (19) . In some parts of the world, for example, food is plentiful in summer but becomes (20) during the cold winter months. Many animals that live in these regions migrate to (21) climates in the fall. They return in the spring when the weather warms up.
Many migrations are (22) reproduction. Numerous animals migrate to breeding areas so that their young have the best chance for (23) . Migratory birds breed in their summer ho
A. adapt to
B. fightagainst
C. control
D. avoid
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