If properly managed, clearing and replanting trees in a 30-year cycle creates both a renewable source of energy and maximum rubber production.

VOA: standard.2009.09.13

That is a maximum If you are sharing your time and energy during this period on Tuesday afternoons, or the arch-field don't work so think carefully about that.

让大家充分发挥自己的能力,如果每周二下午这段时间,你都有时间，精力也很充沛，就可以来上这门课，不过这样你就没时间参加实践活动了,所以请仔细考虑吧。

麻省理工公开课 - 电影哲学课程节选