小华从家里到学校的路是一段平路和一段下坡路,假设他始终保持平路每分钟走60m,下坡路每分钟走80m,上坡路每分钟走40m,则他从家里到学校需10min,从学校到家里需15min.问:从小华家到学校的平路和下坡路各有多远?
解:设平路有xm,下坡路有ym,
根据题意得x60+y80=10
与“最迟者后于清明”句式一致的一项是 ( )
He looks happy because he loves ____ (swim).
A stupid man tells a woman to shut up, while a wise man tells her that her mouth is quite beautiful _______ it is closed.