Philosophy essay

It is 1400 words essay and in this essay you have to think and argue about the question one in supporting the your position and other posing a significant challenge to your position.

I already have choose the topic 1. which is 

1. Read G.E Moore’s “Proof of an external world”. Can we know, on the basis of Moore’s argument, that we have two hands?  
(And below i have attached the pdf from which you have to answer the question)