Which number stand for nothing without its tail?

Which number stand for nothing without its tail? which number comes 1.Which letter comes next?A,C ,F ,J .2.Which number comesnext?2 ,5 ,11 ,23 . Which three letters can stand for English? Which number is the next number?36,25,16, Which is the largest number of four? the number which comes after seven which number is the odd one out which number --- i need?填do?can? Which letter is like the number2? stand stand stand stand! stand stand stand stand