keeps

"The condition for getting a raise at work is meeting your quarterly targets. "

"Regular maintenance of the school's computers ensures they are always working properly. "

"The defenders of the castle stood bravely on the walls, protecting their people from the enemy. "

"The teacher was solicitous about her students' understanding of the difficult concepts. "

"The teacher's supervision of the students ensured a quiet classroom. "

"The lack of sleep resulted in a poor performance on the math test. "

"I told my best friend about my crush confidentially, hoping she wouldn't tell anyone else. "

"The teacher maintained discipline in the classroom by consistently enforcing the rules. "

"His suspicious behaviour brought him to the attention of the police."

"Her diligent practicing on the piano led to a stunning performance at the recital. "

"My grandfather helped me with my math homework. "

"My family keeps milk and other perishable foods in the refrigerator. "