Once there was no zero (零). To write the number sixty-three, people wrote 63. To write six hundred
and three, people wrote 6 3. The space was there to mean "not any" tens. Sometimes people did not
remember the space. It was hard to see and to read.
     Later people used a dot (点) to hold the space. Six hundred and three looked like this 6·3. But the dot
was hard to see.So people put a circle around it like this 6⊙3. Then people could see the dot. They
remembered the space.
    At last,only the circle around the dot was used.It was like a zero. This is one story of how the zero
came to be used.
    Now zero has many important uses. Zero tells how many. Can you tell some other ways zero is
used?
根据以上短文内容，判断下列各句是否符合短文内容。符合短文内容的写“对”, 不符合的写“错”。
1. At first, zero was not used by people.                            (      )
    The space between 6 and 3 was easy to see and to read. (      )
2. When people wrote eight hundred and nine, they would    
    put a cirle with a dot in it between 8 and 9.                    (      )
3. Zero came from the circle around the dot.                     (      )
4. Zero isn't useful in our life.                                          (      )