题目内容：

With advances in transportation and information technology, even the most remote places on Earth are within reach of the traveler. In fact, tourism is now the world’s largest industry, with nature tourism growing the fastest. 1. In response to this increasing appreciation of nature experiences, a new form of travel has arisen called ecotourism.

2. The Nature Conservancy adopts the concept explained by the International Union for Conservation of Nature (IUCN): Environmentally responsible travel to natural areas, in order to enjoy and appreciate nature that promotes conservation, has a low visitor influence and provides for beneficially active socio-economic involvement of local people.

Increased tourism to sensitive natural areas without appropriate planning and management can threaten (威胁) the whole of ecosystems and local cultures.3. Likewise, local communities and can be harmed in numerous ways by crowded foreign visitors and wealth.

4. Ecotourism can provide much-needed reveriues (收益) for the protecting of national parks and other natural areas, which might not be available from other sources.

Additionally, ecotourism can provide a practical economic development alternative for local communities with few other income-generating options. Besides, ecotourism can increase the level of education and activism (积极) among travelers.5.

A. What is ecotourism?

B. The growth of the ecotourism income is also beneficial to the local people.

C. And it makes them more enthusiastic and effective spokesmen for conservation.

D. But most of the tourism in natural areas nowadays is not ecotourism at all.

E. However, this same growth does good to both conservation and local communities.

F. People want to experience nature, but should try not to affect the natural environment.

G. The increase of visitors to ecologically sensitive areas can lead to much environmental damage.