________ can't swallow while they are upside down.
-
Elephant
-
Dogs
-
Rats
-
Chickens
D
Correct answer
Explanation
Chickens cannot swallow while upside down due to their digestive anatomy - gravity is required for food to pass from their mouth to crop and stomach. Option D is correct. Options A (Elephant), B (Dogs), and C (Rats) can swallow in various positions.