The organism which is least similar to the other animals is the blue whale. This is because it belongs to the order cetacea while the other animals belong to the order carnivora. This means that the other animals are carnivorous in their mode of feeding but blue whale is not.
Sediment in rivers gets deposited as the river slows down. Larger, heavier particles like pebbles and sand are deposited first, whilst the lighter silt and clay only settle if the water is almost still.
Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight, creating a brown haze above cities.