adjoining

"The connection between the two classrooms was established by installing a new phone line. "

"The contact between the two teams was fierce during the soccer match. "

"The amount of time it takes to finish my homework is a variable; sometimes it takes me an hour, other times it takes much longer. "

"The plumber joined the two ends of the broken pipe."

"The problem with the project is that the current design flaws are already existing. "

"Letters are the elements of written language."

"We need to bring the balance of power into equation"

"My uncle is a mathematician; he enjoys solving complex equations for fun. "

"The student needed help understanding the algebraic equation on her math homework. "

"The leaky faucet in the kitchen is a problem that needs fixing. "

"You can expand this compact umbrella to cover a large table."

"Where does this document belong?"