You’d better try different ways you can think of maths problems. It’s good for you to learn maths well.
He found the key _____the door.A.of B.to C.for
We all felt _____after we knew the _____news.A.exciting, exciting B.excited, exciting C.exciting, excited
John didn’t go to bed ______he finished his homework. A.until B.after C.while
It took him half an hour _____ the work. A.doing B.to do C.did
The teachers are very friendly ______their students.A.to B.at C.on