Elephants are the largest land animals and they need plenty of living space. They have seasonal migration   routes. As human populations rise, elephant land is being cleared for agriculture and other kinds of development.  When animals are effectively trapped on small areas of land, it restricts the gene pool and also results in a shortage of food. Where elephant reserves   border agricultural areas, elephants are often attracted to leave parks to attack crops and barns. Only the strongest walls will stop an adult elephant (males can weigh 6,000kg), so farmers have great difficulty protecting their fields. In prefix = st1 /India, elephants don't only attack for food. Some even have developed a taste for rice beer. InAssam, elephant-human conflict has resulted in the death of more than 150 people and 200 elephants in the space of two years. Poverty leads to the killing of elephants for meat. If people don't have enough food and their governments cannot afford to enforce poaching  bans, it's not difficult to predict the outcome.  Ivory comes form elephant tusks , which can grow to be 3 meters long. Both male and female African elephants have large tusks. Most new ivory comes from Africa and is sold as a high status material in Asian countries such as Thailand, mainlandChinaandJapan. It can fetch $150 an pound and is carved to make decorations, chopsticks and ink stamps. The conservation   priority   here is to change public attitudes. In some countries in southern Africa, where conservation efforts have been successful, there is not enough room for a growing elephant population and animals have to be killed. A CITES meeting in November 2002 ruled that Botswana,NamibiaandSouth Africamay sell stock-piled ivory, starting in2004. Many conservationists are convinced that _ will fuel the demand for ivory and lead to more illegal poaching, they say it is almost impossible to tell legal from poached ivory. The governments argue that the sales will be used to fund conservation work. The most important thing to protect elephants is   _  .
to build strongest walls to change people's ideas to enforce poaching bans to sell stock-piled ivory instead of illegal ivory