2013-06-13 NASA Scientists Still Dream of, and Plan for, Human Travel to Mars
From VOA Learning English, this is As It Is. Welcome back. I’m Caty Weaver. On the show today, we look into the future of space exploration. The American space agency…
VOA英语教学网 - VOA LEARNING ENGLISH
一个让你免费在线学习VOA英语的好地方! 无须报名, 不收学费, 全年无休, 保证提高! (^_^)
From VOA Learning English, this is As It Is. Welcome back. I’m Caty Weaver. On the show today, we look into the future of space exploration. The American space agency…