【美国小孩学英语】5 眼泪 (1/3)

李瑞波:sometimes,people cry when they are sad,other time people cry tears of joy .but ur eyes make tears all the time, whether u crying or not. did u know the tears help our eyes healthy?they keep our eyes from drying-out,a special area of the eyes drips all the time,it keep the eye damp.