Read the following passage and mark the letter A, B, C or Don your answer sheet to indicate the correct word for each of the blanks.

Ecotourism is a (44)_____ business that many tour operators cite as being helpful to nature. Every year, millions of people descend on protected and pristine natural areas to observe rare species. (45)_____, a new report casts doubt on the value of this form of tourism. In fact, it suggests that ecotourism is more damaging than helpful to nature. Details are in a report published in the journal 'Trends in Ecology and Evolution'.

Researchers believe tourists are disrupting animals in their natural habitat. They pointed to a recent event where sea turtles in Costa Rica had problems laying their eggs because of the hordes of tourists (46)_____ had congregated to watch the turtles' nesting habits.

The report says that ecotourism is making animals bolder and that this could (47)_____ the animals. A regular human presence might make animals tamer and less cautious about (48)_____ animals around them, and this could put them at risk of being attacked by their natural threats.

The report says that ecotourism is making animals bolder and that this could (47)_____ the animals.