Chalk produce, and thus widely used in the developing world, calcium-based chalk can be made where the crumbling particles are larger and thus produce less dust, and is marketed as "dustless chalk". Colored chalks, pastel chalks, and sidewalk chalk (shaped into larger sticks and often colored), used to draw on sidewalks, streets, and driveways, are primarily made of gypsum. Chalk is a source of quicklime by thermal decomposition, or slaked lime following quenching of quicklime with water. In southeast England, deneholes are a notable example of ancient chalk pits. Such bell pits may also mark the sites of ancient flint mines,
Vezo people catches that men bring them. With what they earn, women buy rice, the staple food, other essential foodstuff and a variety of luxury items. Children go to school in the one village school building, where there are two designated teachers. However, due to the deterioration of public administration in Madagascar, the building and the teachers are hardly ever occupied. Whenever children are in the building, and if the teacher has not run out of chalk, the teaching largely consists in copying letters, numbers, and short sentences from the blackboard onto the child's own A5 size blackboard. Understandably, the many children