who's chest size is biggest

華華這天在做科學功課.他碰到如下的一道題:

Danny measured  the  chest size of his friends when they breathed in and out.
what was Danny trying to find out?

華華略一思索,即刻寫下答案:

he was trying to find out that who's chest size is biggest.





 正確答案是:
he was trying to find out if the chest size changes when breathing in and out.