zero ideal

例句：

1. 1. The zero in the number means there is no quantity.
   数字中的零表示没有数量。
2. 2. The zero in the account shows there is no money.
   账户中的零表示没有钱。
3. 3. The zero in the decimal system represents a point of division.
   十进制系统中的零代表一个分点。