"But if you look into the Mekong delta, for example in Vietnam, it has shown the 30-year cycle, but the phase and amplitude is going up and then going up like that."

VOA: standard.2009.12.21

And what we know is that very often we enter a downward spiral, a vicious cycle when we go into this narrow and constrict mode.

我们知道经常会进入下行螺旋，一个恶性循环，当我们进入狭窄收紧的模式。

哈佛公开课 - 幸福课课程节选

And what we know is that very often we enter a downward spiral, a vicious cycle when we go into this narrow and constrict mode.

我们知道经常会进入下行螺旋，一个恶性循环，当我们进入狭窄收紧的模式。

哈佛公开课 - 幸福课课程节选