新概念英语第一册视频全集免费

视频简介

In 2016 filmmaker/photographer Pete McBride and writer Kevin Fedarko set out on a 750-mile journey on foot through the entire length of the Grand Canyon. More people have stood on the moon than have accomplished this task. Their quest was more than just an endurance test — it was also a way to draw attention to the unprecedented threats facing one of our most revered landscapes...。