The correct options are
B bursting of water pipe’s during winter.
C preservation of the aquatic life during the very cold weather.
D icebergs floating on water.
In winter nights, when the temperature starts falling below 4 ∘C, water in pipelines expands and it exerts large pressure on the pipes, causing them to burst.
Anamalous expansion of water helps in maintaining the temperature deep under the pond, thereby helping in preserving the aquatic animals.
Generally, density of solids is greater than that of liquids. But in case of water, liquid density is greater than the density of ice. Therefore, ice floats on the water surface.