These are what are left needing answers. 
Complete this sequence of letters: o, t, t, f, f, s, s, _, _, _.
A certain five letter word becomes shorter when you add two letters to it. What is the word? 
Which is the word in English that has nine letters, and remains a word at each step even when you remove one letter from it, right up to a single letter remaining. List each letter as you remove them, along with the resulting word at each step. 
Oh and Koi707 good guess and you are very close!