Their parents believed all children needed physical activity to grow healthy and strong.

VOA: special.2010.05.26

What happens when we have a strong physical immune system?

如果我们有强大的生理免疫系统会怎样？

哈佛公开课 - 幸福课课程节选

He said the U.S.team has strong tactics, discipline and is very physical.

VOA: standard.2009.06.29