Answer:
Computer
Explanation:
A common noun is the type of noun that denotes the names of non-specific things such as people, animals, etc.
From the example given, the common noun there is "computer" because it does not mention a specific thing like the type of computer.
A Pictograph uses pictures to represent a particular number of items.
I'll just rewrite the sentence how it's supposed to sound...
My bike tire was low, i wasn't surprised that it went flat just as it began to rain.
