nullify

"The teacher's announcement nullified the extra credit assignment. "

"He is a student of life."

"The plans for many important buildings were once publicly available."

"Let me tell you how it happened."

"This invalid contract cannot be legally enforced."

"My parents are legally obligated to provide for my needs until I turn eighteen. "

"All participants must adhere to the rules."

"We went out for a picnic in the forest."

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

"The school's announcement of the cancellation of the field trip disappointed the students. "

"strict embrace"

"Marriage is a contract."