[填空题]Rabies is an ordinarily infectious disease of the central nervous system. It is caused by a virus and, (51) a rule, spread chiefly by domestic dogs and (52) flesh-eating animals. Man and all warm-blooded animals are susceptible (53) rabies. The people of (54) Egypt, Greece and Rome ascribed rabies to evil spirits (55) ordinarily gentle and friendly animals suddenly became vivacious and violent (56) evident cause and, (57) a period of maniacal behavior became paralyzed and died.
Experiments (58) out in Europe in the early nineteenth century of injecting saliva from a rabid dog (59) a normal dog proved that the disease was infectious. Preventive steps, (60) as the destruction of stray dogs, were taken and (61) 1862 the disease was permanently eliminated in Norway, Sweden and Denmark. Though urban center on the continent of Europe were cleared several times during the nineteenth century