补全短文
A. marine B. have discovered C. slows Phrases: A. This turbulence muses friction and【T1】______the fish down B. Another kind of【T2】______animals is dolphin C. Biologists studying the dolphin【T3】______that 【T4】______This seagoing mammal has been clocked at speed of 32 kilometers(20miles)an hour.【T5】______, like the shark, the animal's efficient locomotion can be traced to its skin. A dolphin's skin is made up in such a way that it offers very little resistance to the water flowing over it. Normally when a fish or other object moves slowly through the water, the water flows smoothly past the body. This smooth flow is known as laminar flow. However, at faster speeds the water becomes more turbulent along the moving fish.【T6】______