Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks

Ecotourism is booming and many tour operators say this is helpful to nature. ___(1)___ year, millions of people visit protected natural areas to observe rare species. ___(2)___, a new report casts doubt on this form of tourism. The report, published in the journal "Trends in Ecology and Evolution", suggests that ecotourism damages more than ___(3)___ nature. Researchers believe tourists disrupt animals in their natural ___(4)___. They point to a recent event in Costa Rica where turtles had problems laying their eggs because of the many tourists ___(5)___ had gathered on the beach to watch them.