唐天文学接一行，在世界第一次测出 __________的长度。

     One afternoon just before Christmas, an old man was walking    1    the city center.The shop were
all    2    of good things and crowded with    3    shoppers. Sunddenly he saw a dirty boy    4    on the
ground crying sadly. When the kind old man asked him why he was crying, the little boy told him that
he had    5   a ten-penny (便士) piece that his uncle had    6   him. At once the old man pulled out a handful
of coins. He    7   out a shining new ten-penny piece and handed it to the poor child."Thank you very
much," said the little boy, drying his    8  . He cheered up at once.
     About an hour    9  , the old man was making his way   10   home by the same road.
     To his   11 , he saw the dirty boy in the same place, crying sadly as   12  . He went up to the boy and
asked him   13   he had lost ten-penny piece he had just given him as well. The boy told him that he had not
lost the second coin   14   he still couldn't find the first one. "If I could find my own piece," he cried, "I would
have   15   pennies now."