Why do birds eat nectar from only certain flowers?

Explanation:

Birds with longer, thinner bills, such as hummingbirds, bananaquits, and sunbirds, insert their bills into the flower so they can lick at the nectar directly. ... Nectar-eating birds are called nectivorous if nectar does make up a large proportion of the majority of their diet, such as with hummingbirds.

metamorphism is the change of minerals or geologic texture (distinct arrangement of minerals) in pre-existing rocks (protoliths), without the protolith melting into liquid magma (a solid-state change). the change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. i hoped i !

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.