本期内容：
The world's last surviving male northern white rhino has died after months of ill health, his carers said.
Sudan,45,lived at OI Pejeta Conservancy in Kenya.
He was put to sleep on Monday after age-related complications worsened significantly.
His death leaves only two females-his daughter and granddaughter-of the subspecies alive in the world.
Hope for preserving the northern white rhino now lies in developing in vitro fertilization(IVF).
Carer: 看护者
Complication: 并发症
Subspecies: 亚种
Preserve: 保存
In Vitro Fertilization ( IVF ): 体外受精 |