That's why having dog-slobber, kitty hairballs and muddy pawprints around your mother while you're in utero might get your immune system off to a proper start even before you're born!

这就是为什么当你在子宫里时，在你母亲身边有狗的口水、猫咪的毛球和泥泞的爪印，可能会让你的免疫系统在你出生前就开始正常运转！