Fish live in water. They use their special organ（器官） called gills（腮） for breathing. Some fish are dangerous to humans. Here are the world's most dangerous fishes.
Electric Eel（电鳗） - It is a South American fish. Electric eels are long and usually gray-brown in color. The electric eel can reach up to 9 feet long and can weigh up to 22 kg. The fish has a mouth. It is rich in blood vessels（血管）. The fish can use them as lungs（肺）. Its tail has the electric organ that gives off 300 - 650 volts of electricity.
Stonefish - These venomous（有毒的） fish are generally found in the waters of the tropical Indo-Pacific. These fish have small eyes, large heads and mouths. If you ever see one, stay away from it.
Piranha（水虎鱼） - There are more than 60 kinds of Piranha fish. These meat-eating fish have sharp（尖利的） teeth. Most of the Piranha fish eat plants or anything that they can find.
Puffer Fish（河豚） - It can inflate（使膨胀） itself with water and air to turn into a ball several times its real size. One puffer fish has enough toxins（毒素） to kill about 30 humans. There are total 120 kinds of puffer fish all over the world.

Four World's Most Dangerous Fishes
Electric Eel	◆It comes from (1) and it is long and gray-brown. ◆The blood vessels in its mouth can (2) as lungs. ◆The electric organ in its tail can give off 300 - 650 volts of electricity.
(3)	◆They live in the waters of the tropical Indo-Pacific. ◆They are venomous and they have small eyes, large heads and mouths.
Piranha	◆They have (4) . ◆They feed on meat, plants and so on.
Puffer Fish	◆It can inflate itself to turn into a much bigger (5) . ◆It can kill humans with its toxins.

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