The teacher rubbed against the blackboard, getting chalk all over his back.老师擦黑板时弄得背上满是粉笔灰。There were chalky bits in the bottom of the drink.饮料底层有粉笔灰一样的东西。Tut! I've got some chalk on my coat.啧！我外套上弄上一些粉笔灰了。They used to put chalk dust on the underneath of the horse's saddle.他们以前常在马鞍底下撒些粉笔灰。