【答案解析】Rain forests are compared to the earth lung (lung of the earth), whose main function is the production of carbon dioxide and regulation (conditioning) of the world climate (is to produce.., and condition...). Because of the growth (increase) of the local population (residents) and the demand for timber, rain forests continue to shrink (keep shrinking) / the size of rain forests is diminishing (declining / becoming smaller), posing a direct threat to (directly threatening) the survival of many rare species. Seeking (pursuing) short-term interests will lead to long-term pain (suffering). Biodiversity conservation (protection of biodiversity) involves (makes it necessary to) sacrificing (giving up) one's personal interests. Unfortunately, the governments of countries concerned have yet to reach (have not reached) consensus (an agreement).