同学们在准备托福写作的时候要有自己的计划。在备考的时候可以针对历年托福写作题目进行练习，总结一些写作技巧。出国留学网托福栏目为大家带来“托福写作范文高分鉴赏”，希望对大家有所帮助哦!
New findings in scientific areas can examine and challenge previous assumptions. A recent finding concerning the meerkat, a burrow-dwelling animal in the African grasslands, has cast doubt upon the conventional ideas of altruism, the type of behavior in which an animal sacrifices its own interests for the benefit of another.
Meerkats were previously thought to be a typical altruisticanimal. When the other meerkats feed, there is usually one meerkat watching out for predators. The sentinel meerkat gains nothing, it seems, for it can neither eat nor escape quickly and successfully after raising an alarm.
However, in the new findings, it's shown that the sentinel meerkat has already eaten food before standing guard, thus contradicting the thought that it has an empty belly while on the lookout. In addition to this, the sentinel is the first to see a predator, so it is the first to escape. It is also placed nearest a burrow, making it relatively easier to flee. Moreover, its alarm calls may cause the groupeither to gather or to spread rapidly, which may attract the predator's attention, providing thesentinel a better chance to escape.
The same is with supposed human altruistic behavior. Organ donation to strangers may beconsidered an unselfish act, which provides little reward to the donator. However, by donating hisorgan, the donator may most p...