but now she faces a long return journey 但前面等着她的是一段漫长的返程
so he can't stay in these chilly waters for long. 因此它不能在冷水里待太久
Not so long ago, these whales faced a graver threat. 不久之前 这些鲸鱼面临着更严重的威胁
But free riders are only tolerated for so long. 不过搭便车的也得意不了多久
They should be safe, as long as they remain quiet. 这样应该很安全 只要保持安静
at the top of the dunes, and it won't last long. 难以触及 而且不会久留
he can now set off on the long journey home. 他开始漫长的归家旅程
desert-living elephants must also undertake long journeys 沙漠象也必须踏上旅途