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.

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.