Allis,

I think, upon third review, what the Professor means to imply is that by the end of this week, if we have posted once per week since the begining of the term, we are to have posted a total of four times with an introductary post and three times without. Which is to say; if you have posted one relevent post per week post once more before Sunday and you'll be okay. I think. It's a little obtuse.