JosB's Homework

As most of you know, JosB loves to follow Sai Sai.
Recently, whenever Sai Sai is doing homework, JosB will keep pointing at Sai Sai.
And he will say, "Joshua's homework ..." !
Oh, JosB has homework, too ?!

Then, we have to give him some paper and colour pencils.
Look ! He's so concentrated :)
Hope that he could do the same when he goes to school ...


But, what's his homework ? which subject it is ?
ha..ha..ha...