He takes everything KaBOOM knows about building playgrounds and putsthat information online in a simple,easy-to-use design.

VOA: special.2010.11.05

It's not easy to devise this and the concept is very simple.

设计保单并不那么容易,仅仅一条概念太单薄了。

耶鲁公开课 - 金融市场课程节选

It's not easy to devise this and the concept is very simple.

设计保单并不那么容易,仅仅一条概念太单薄了。

耶鲁公开课 - 金融市场课程节选