英语时差：狼到中年（上）

Picture an elk walking through the forest, looking for some berries to nibble. Then, suddenly, a pack of wolves leaps from the bushes, surrounding the startled animal. The wolves close in. The elk looks for an escape route, but the predators tighten the circle. The elk is a goner, right? Maybe. But it depends partly on the age of the wolves. According to one study, wolves’ hunting skills peak around age three, and then their hunting prowess starts to decline. By the time wolves reach old age, around the age of six, they’re no longer the same hunters they were as youngsters.