Liquid water, which is necessary for life as we know it, continues to exist on the surface of Earth because the planet is at a distance, known as the habitable zone, far enough from the Sun that it does not lose its water to the runaway greenhouse effect.
Answer is
body-brain barrier.
Explanation:
Mannitol injection is used to reduce swelling ande pressure around the brain.
It enhances flow of water from tissues including cerebrospinal fluid and the brain into plasma and interstitial fluid.
The correct option is A, FEEDING HABIT AND MIGRATION. From the passage given above, it can be seen that seagulls are scavengers, they usually eat from garbage dumps while wild geese eat seeds and insects, thus they differ in feeding habit. In term of migration, seagulls does not follow seasonal pattern of annual migration while wild geese do. These are the contrasts between the two birds.
That would be the independent variable :)
