First, fill in the blanks. (1 minute per grid, ***20 points)
The length of a number is 5 parts per billion, 5 parts per million, the highest digit is 5, and all other numbers are 0. This number is written as (), and the mantissa after omitting tens of thousands is ().
The decimal unit of 2.0.375 is (), and it has () such units.
3.6.596596 ... is a circular decimal (), which is simply called () and two decimal places are ().
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