fortress

"The castle served as the king's stronghold, protecting him from invaders. "

"The school's fortification project involved adding high walls and security cameras to improve safety. "

"I will purchase the vacation package if you will include car rental."

"Maria is achieving excellent grades in her math class this semester. "

"I brush my teeth regularly to prevent them from turning yellow."

"My sometimes neighbor, a retired teacher, still visits the school occasionally. "

"My sister got a permanent for her wedding, which was supposed to last for several months. "

"It is generally known that the Earth is round."

"The broken chair leg was supported by a precarious makeshift of stacked books and duct tape. "

"The ancient mountains served as natural fortresses, protecting the valley from invaders. "

"Any penetration, however slight, is sufficient to complete the offense."

"We enjoyed a glass of fortified after dinner. "