Guinea Bissau has Africa's second lowest rating on the U.N.'s Human Development Index measuring life expectancy,education, and standards of living.

VOA: standard.2009.04.24

I study child development for a living and I'm interested in several questions.

我主要研究儿童的发展,我对很多问题都感兴趣

耶鲁公开课 - 心理学导论课程节选