concavity

"Hold the pencil like this."

"The being in the classroom was quiet today. "

"The inside of the bowl is a concave shape. "

"The smooth surface of the kitchen table was perfect for setting the dinner plates. "

"The birds had built an amazing structure out of sticks and various discarded items."

"to allow a servant his liberty;  to allow a free passage;  to allow one day for rest"

"They completed the first series perfectly."

"My sister used a spoon to eat her soup. "

"The current state of the project is that we are behind schedule. "

"By the action of electricity, the water was resolved into its two parts, oxygen and hydrogen."

"The school is located just outside the town, without the main shopping area. "

"I spilled some sticky juice on the kitchen floor."