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False or Not Given

　　Sample exercise

　　Shark Senses

　　THE SHARKS SIXTH SENSE: The shark has all the senses that we humans do but they also have one we dont have. Tiny pores on the snout leads to jelly-filled sacs known as ampullaes of Lorenzini. This sense can detect very weak electrical fields that can detect electrical vibes as weak as half a billionth of a volt. Struggling or scared animal creates a strong electrical current, which flows through the water, and even though it gets weaker as it travels away from the animal, sharks can pick it up. Every animal sends electrical vibes. A shark can find animals under the sand, and at night, and when at the last moment of attack when the eyes are rolled back and it cannot see. In many cases when doing shark research the shark would attack the boat and other objects instead of the food offered. Humans used to think that the shark was just a stupid, crazy eating machine that went after anything. It turns out however that the shark when coming for the prey would roll its eyes back and have the ampullaes of Loranzini direct it to the prey. The boat gives out very strong electrical vibes which confuse the shark and direct it to the boats direction, and since the shark cannot see at the moment it would not know the boat is not the prey. Hammerhead sharks have a large number of ampullaes of Lorenzini on their heads. Hammerheads use their heads like mine sweepers to find stingrays, and other prey in the sand. Large number of hammerheads can be found near underwater volcanoes which attract them from miles away with their electrical fields. The rare and strange goblin shark has a strange snout hanging over is head which may be used the same way as a hammerheads head and help it hunt in the deep dark water it lives in. Goblin shark teeth have been found in underwater electrical cables.