underpinnings

"My friend told me there was something in the box, but I didn't know what it was yet. "

"You should underpin the mine roof to prevent further collapse."

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

"He studied masonry for five years."

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

"The bridge's sturdy support beams prevented the structure from collapsing. "

"Please tighten that screw a quarter-turn."

"The child was sinking his toes into the warm sand at the beach. "

"The old wooden table had weak supports and wobbled easily. "

"The old building's roof collapsed during the storm, sending debris everywhere. "

"The school's political represented the students' concerns to the principal. "

"The foundation of his institute has been wrought with difficulty."