Change the following sentences into interrogative: Volta made the first battery in 1800. They have found an encyclopaedia. The photography shows the great beauty of Nepal They hid in one small room for four years. The Greeks returned to their own land. The other soldiers got into the ship. Archaeologists dig under the ground. They were going down the mountain. His gloves fell down. He has already phoned his friends. They bought a new house. I can milk a cow. They moved to London in 1998. They are working in the field.