Dustfrom volcanic eruptions that blocks the Sun's warming radiation has been proposed as an explanation alternative to Milankovitch cycles for the cause of ice ages.
来自火山喷发的灰尘阻挡了太阳温暖的辐射，这被认为是导致冰河时代的另一种解释。
2
When you cut your finger, if some dustfrom the floor goes into the cut, some germs would go into your finger.