Do you know ....

Do you know .... Do you know .... This is awesome - I bet you didn't know this...Letters 'a', 'b', 'c' & 'd' do not appear anywhere in the spellings of 1 to 99(Letter 'd' comes for the first time in Hundred)Letters 'a', 'b' & 'c' do not appear anywhere in the spellings of 1 to 999(Letter 'a' comes for the first time in Thousand)Letters 'b' & 'c' do not appear anywhere in the spellings of 1 to 999,999,999(Letter 'b' comes for the first time in Billion)AndLetter 'c' does not appear anywhere in in the spellings of entire English Counting******