WHEN THE HUBBLE SPACE TELESCOPE FOCUSED FOR TEN DAYS ON A DARK PAT...

17. When the Hubble Space Telescope focused for ten days on a dark patch of the sky size of a grain of sand, what initially appeared to be empty space ...thousands of distant galaxies. A. turned out to be filled with B. it turned out to be filled C. turning out to be filled with D. and it turned out to fill