“Would their children chalk it in doorways before they knew its meaning as a trademark?”

“Pore-filling cementation is also common during the diagenesis of chalks, resulting in rapid porosity loss.”

“The coccolithophorids range in age from Triassic to Recent, and form a major constituent of Mesozoic and Tertiary chalks.”

“For the more artistically inclined, sidewalk chalks in a multitude of hues will keep pavement Picassos occupied.”

“Children in one of the country's poorest neighbourhoods have chalked up an astounding improvement in exam scores.”

“Carefully and deliberately a list of headings was chalked on the blackboard.”

“The crowd broke into renewed cheering when this was chalked on a blackboard.”