Sharp concern for environmental protection, similar to the belief in ____1_____ or the opposition to plastic surgery, is a necessary ___2_____ to people in the upper class world. But people have different opinions about it. Therefore, how can we make the right choice among so many different and conflicting proposals put forward in the name of environmental ____3_____? To answer the question, it is necessary to follow a rule for making environmental choices: the so-called _________4___________, which advocates that combating ecological changes that directly do harm to human health and safety is an ________5_____________. The criterion for making environmental choices indicates that nature should ___6___ human beings, and that human beings should protect nature only when their own_________7___________ are not affected. While other people put forward a different rule, called a _______8____________________, which is characterized by excessive earth ___9____, human interests should be given priority over those of animals or nature and nature should be ____10_______ to human beings because human interests are more important than those of nature.