Many people believe sharks are dangerous and will always try to hurt or even kill humans.   .A shark exhibition at the National Aquarium（水族馆）in Baltimore，USA.proves this．Visitors can touch young sharks，see their eggs develop and watch a dozen different species swim smoothly around a huge tank．
Most people fail to realize that shark attacks do not happen very often．Humans are more likely to be killed by lightning than by a shark.   .There kids can learn, from an early age, not to fear sharks．
“People fear what they don’t know，”said Nancy Hotchkiss，an organizer of the exhibition．“Sharks have been around for 400 million years and play an important role in the ocean’s food chain．We want people to discover that sharks are amazing animals that need our respect and protection．”   . A study，published in January in the US magazine，Science，found that almost all recorded shark species have fallen by half in the past 8 to 15 years．
Thousands of sharks are hunted in Asia for special foods，and many others get caught in nets，while fishermen are hunting other fish. 
“Some fishing methods are actually cleaning out the ocean for sharks，”said Dave Schofield，the manager of the aquarium’s ocean health program.

A．They can watch them develop inside their eggs and feel the skin of the older swimmers

B．In fact，94 percent of the world’s 400 species are harmless to humans

C．About 100 million sharks are killed every year around the world by humans．

D．It is a worrying situation but some areas have put measures in place to protect these special fish．

E．And to make this point clear，the museum has set up a special touching pool for children．
F．Sharks can smell and taste blood,and trace it back to its source
G. More than half of the sharks caught are smaller than l meter long．