卡尔。萨根不仅是一位非常成功的科学家和大学教授，他还是一位成功的作家。

Carl Sagan was an extremely successful scientist and university professor. He was also a successful writer.

youdao

卡尔。萨根不仅是一位非常成功的科学家和大学教授，他还是一位成功的作家。

Carl Sagan was an extremely successful scientist and university professor. He was also a successful writer.

youdao