Что лишнее? б. скрипка, виолончель, арфа, контрабас

mark and his friend are thirteen years old.and they are very sporty. they often go to the gym - at least three timesa week. mark does exercises to make his arms strong.he can t walk because of a car accident, so he goes everywhere in wheelchair. but it doesn t stop him doing the things that boys our age want to do.