Rous sarcoma virus

例句：

1. 1.The virus is responsible for the development of cancer in humans.
   这种病毒是人类癌症发展的原因。
2. 2. The researcher discovered a new strain of the virus that could be used to fight it.
   研究人员发现了一种新病毒株，可以用来对抗它。
3. 3. The virus has been found in many animals, including humans and animals.
   这种病毒已经在许多动物中被发现，包括人类和动物。