Correct or Improve the translation of the following English sentences.原文：Obama also called climate change and nuclear proliferation “challenges that neither of our nations can solve by acting alone." 译文：奥巴马也把气候变化和核扩散称为“我们两国都无法单方面解决的挑战” 。

Correct or Improve the translation of the following English sentences.原文：Obama also called climate change and nuclear proliferation “challenges that neither of our nations can solve by acting alone." 译文：奥巴马也把气候变化和核扩散称为“我们两国都无法单方面解决的挑战” 。

奥巴马也把气候变化和核扩散称为“我们两国都无法单方面应对的挑战”。