I use a clock to wake me up because at six o'clock each morning the train comes by my house.
17. Our attention was drawn to the eight-year-old girl who was _______ perfectly at the piano.
16. He made another wonderful discovery, __________ of great importance to science.
15. Great changes ______ in the city, and a lot of new buildings ______.
14. I thought she ______ like something to eat, so I have bought two pieces of bread.
13. Recently I bought a house, _______ was very reasonable.