四、文意選填：15% 

    Six hundredmillion hungry rabbits can be harmful. They ate native plantspecies __61__ theydisappeared. They competed forfood and shelter __62__ native animals.And they were a nightmare forcattle and sheep farmers, __63__ animals couldn’t get enough grassto eat and starved. The rabbits didsome good, of course. They provided food __64__ poorfamilies. They helped fur and __65__ industries. Buttheirimpact on the environment andmajorlivestock economy was __66__ negative to be ignored. Peopletried trapping them. They even built a huge wall againstthem.Aftermuch testing,the deadlymyxoma viruswas unleashed on Australia’srabbits. Itwas a huge success. Cattle and sheep ranching bounced back, andthreatened plants were better protected.However,rabbits became __67__ to the virus.Another viruswasintroduced, and it had good results. The rabbits are under controlfor now, and the continent haslearned tobe __68__with newspecies.
【題組】61