origin of agriculture

例句：

1. 1.The origin of the species is unknown.
   这种物种的起源尚不清楚。
2. 2. The origin of the disease is still under investigation.
   这种疾病的起源仍在调查中。
3. 3.The origin of the language can be traced back to ancient Egypt.
   这种语言的起源可以追溯到古埃及。