英语四级改错精练(6)

　　The first man known to use a signal other than a
　bonfire used a chandelier. He was lord of a castle that
　stood near a rocky seacoast. He hang the chandelier, 1.__________
　containing many large tallow candles, in the highest
　tower of his castle. Thus he warned passing ship from 2.__________
　the danger along the coast.

　Candles soon became the common fuel for signal
　lights. They were later replaced by oil lamps, that 3.__________
　could burn larger and brighter. Kerosene and gas lamps 4.__________
　also tried. These are still in use now in some smaller
　lighthouses. But today most lighthouses sent electric 5.__________
　light blazing out over the sea.

　The ancient fire signals only say "Danger! Keep off!".
　But the modern lighthous also identifies it in a code 6.__________
　known to all shipping. Most of the great lights have
　their own special signals. The light may be one that
　blinks--as a giant firefly in the night. Or it may be 7.__________
　a revolved light that is red then green. Or it may be 8.__________
　only white. But however the signal, it is sent very 9.__________
　regularly. A ship within its ranges is never at a loss to
　know which lighthouse it is, and where it is being 10.__________
　located