你必須為夢想而奮斗。你必須為之犧牲并努力工作。
建筑師必須是一位科學(xué)家。
海洋不僅是食物的來源，也是我們星球生態(tài)系統(tǒng)的重要組成部分，我們必須為子孫后代保護它。
The true value of a forest can't be measured in board feet alone.
I try to get rid of people who confidently answer questions about which they don't have any real knowledge.