As America's first environmentalist, John Muir lived his life forever daring to undertake new adventures
出自-2013年6月听力原文
Encourage people to undertake adventures
出自-2013年6月听力原文
You might expect that the student who had undertaken the most exhausted search would be the most satisfied with their final decision, but it turns out that's not true.
出自-2011年6月听力原文