challenge

"an enthusiastic lover of art"

"The competition for this job is strong."

"We challenged the boys next door to a game of football."

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

"That was an enjoyable day; I had a lot of fun."

"The school's procedure for returning lost items involves filling out a form and leaving it with the office staff. "

"The difficulty of the math problem made it hard for many students to solve it. "

"The application required a countersign from the department head to validate the principal's signature. "

"The intellectual presented a compelling argument for a new school policy. "

"He completed the assignment on time."

"The confrontation between the two students escalated when one accused the other of cheating on the exam. "

"The complicated instructions on the new software difficult me from completing the project on time. "