Which areas of the ocean experience the greatest variation in salinity?

Of the five ocean basins, the Atlantic Ocean is the saltiest. On average, there is a distinct decrease of salinity near the equator and at both poles, although for different reasons. Near the equator, the tropics receive the most rain on a consistent basis. Oceans and seas cover roughly 70 per cent of the world, and contain about 97 per cent of the Earth's water, and yet, the water is undrinkable due to the salt levels

the answer to your question is tooth decay.

answer: grassland biomes are closer to the equator and receive more rain.

grasslands are biomes that are dominated by grasses rather shrubs and trees. savanna are biomes that exhibit grasses, shrubs and small tree as vegetation. grasslands are located near the equator of the earth. these are found in north america. savanna biomes are found in africa, south america, australia and india. grassland exhibit moderate climatic conditions, it receives   amount of rainfall higher than savanna.   therefore, savanna exhibit dry and hot climatic conditions.