Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 44 to 50.

Environmentalists often fear that tourists will trample all over sensitive natural resource areas, but tourism may bring the needed and only economic incentives to help drive conservation, said Bynum Boley. Ecotourism and natural resource conservation already have a mutually beneficial relationship that is ideal for creating a sustainable partnership.

"Ecotourism destinations benefit in the form of enhanced tourism competitiveness from the protection of quality natural resources," he said. "Meanwhile, the conservation of these natural resources is increasingly valued since these pristine natural resources are the foundation of the ecotourism industry and the driver of all economic benefits associated with ecotourism."

Tourism is a $7.6 trillion global industry, provides 277 million jobs and is a primary income source for 20 of the world's 48 least-developed countries. It also subsidizes environmental protection and helps protect, conserve and value cultural resources that might otherwise be undervalued by the host community, Boley said. In the newspaper, Boley and co-author Gary Green said that despite past tension between the tourism industry and environmentalists, the two should team up as allies to fight off increasing conversion of land away from its natural state. Ecotourists not only provide a boost to the economy in such places, they can also motivate landowners into keeping the environment in its natural state instead of converting it into something unsustainable. They could also influence the public perception of conservation, Boley explained, which does not often favor environmental protection.

“The public has become increasingly less prone to respond to environmental messages,” he said. “Economic messages are needed in order to attract the public's interest.” Too often, Boley and Green said, unique natural resource areas are converted into urban, suburban and agricultural developments without considering their ecotourism potential. In addition to the lost ecotourism revenue, there are a host of negative environmental consequences such as biodiversity loss, water and food shortages and the land being unable to mitigate the effects of climate change. These areas are not valued for their unique attributes or the valuable natural resources they provide, Green said, “so we lose them.” Tourists have historically been seen as having a negative impact on the environment. Critics complain that they violate fragile and threatened natural environments while contributing to greenhouse gases from the increased number of flights to these exotic and often remote locales. While these criticisms are justified, Boley and Green said responsible programs promote education of ecological conservation and environmental sustainability, fostering a greater understanding and appreciation of these exotic areas.

John will start studying for the exam _____. A. before he finished his lunch