ridges

"The zookeeper carefully observed the quadruped as it munched on its food. "

"My teacher explained the new math concept, and I understood it perfectly. "

"The horizontal of the classroom desk is sturdy enough to hold a large stack of books. "

"The aquifer's underwater supply of fresh water is crucial for the town's water system. "

"My sister is very helpful, especially when it comes to organizing things. "

"The atmospheric pressure in the classroom was tense after the surprise announcement. "

"The stretching of the rubber band showed its elasticity. "

"The shelf is projecting about a foot from the wall. "

"The medieval city's fortifications, including its high walls and deep moat, protected it from attack. "

"To proceed on a journey."

"The tree trunk had a large protuberance where a branch had been broken off long ago. "

"The artist's painting represented the beauty of the sunset over the ocean. "