【词组讲解】
Perfect conditions mean that you aren't in water or sweating, two things that usually go hand in hand with the sun. This also doesn't reflect sunscreen that can rub off from your clothing.
理想的条件意味着你不是在水里或出汗。而这两个事情通常和阳光密切联系在一起。但这也并不反应防晒霜会被你的衣服所擦掉。
rub off 表示“ (使)摩擦掉;(使)减色”,例如:
A shame does not rub off.
耻辱无法抹灭。
With the passing of time, some of the glitter of the achievement has rubbed off.
随着时间的流逝, 这一光辉的成就已有所减色。