the eng of 6碳醣,5碳醣,4碳醣,3碳醣,2碳醣 & 1碳醣 ?

6 C sugar, 5 C sugar, 4 C sugar, 3 C sugar, 2 C sugar, 1 C sugar

C = carbon
They refer to the number of carbon atom in the carbon ring of the carbohydrate.
As far as I know, there aren't any1碳醣......