Zanzibar，Tanzania--Hundreds of dead dolphins were washed up on Friday along the shore of a popular tourist place on Tanzania’s northern coast．Scientists have ruled out poisoning．
It was not immediately clear what killed the 400 dolphins，whose dead bodies lied along a 4-kilometer coast of Nungwi，said Narriman Jidawi，a marine biologist at the Institute of Marine Science in Zanzibar．But the bottleneck dolphins，which live in deep offshore waters，had empty stomachs，meaning they could have got lost and had been swimming for some time to reorient themselves．They did not die of hunger and were not poisoned，Jidawi said．
In the US，experts were looking into the possibility that sonar(声呐)from the US submarine could have caused a similar incident in Marothon，Florida，where 68 deep-water dolphins stranded(搁浅)themselves in March 2005．
The deaths are a blow to the tourism industry in Zanzibar，where thousands of visitors go to watch and swim with dolphins．Villagers，fishermen and hotel residents found the dead bodies and told officials．Mussa Aboud，Zanzibar’s director of fisheries，went on state radio to warn the public against eating the dolphins’meat，saying the cause of death had not been found．
The Indo-Pacific bottlenose，commonly known as dolphins，are the most common species in Zanzibar’s coastal waters，with bottlenose and humpback dolphins often found in mixed-species groups．
63．According to the passage，the bottleneck dolphins ．
A．are often attacked by submarine in deep water
B．find it hard to find enough food near the coast
C．often fall ill along the shore of a tourist place
D．1ike living in the deep waters near the coast
64．The underlined word“reorient”means ．
A．lose their way B．find their way
C．look for food D．fight against enemies
65．What can we infer from the passage?
A．The dolphins died because of the sonar from US submarines．
B．The dead dolphins can not be eaten as they are poisonous．
C．The US experts are researching sonar at present．
D．The ability of locating is extremely important for dolphins．
66．What would be the best title for the passage?
A．400 dolphins died along the coast of Nungwi．
B．Dolphins are facing increased risk of death．
C．It’s necessary for us to protect dolphins．
D．Nungwi is famous for many dolphins there．