Choose the right grammatical form in each gap to complete the text

I'm Sam. I live in a small house with my mum. I want to show you my room. I like playing computer games at[those|these|that|this] desk near the window. Also, I have some stuff on it. [These|That|This|Those] are a ball and a cup. Let's look at my chest of drawers. My mum prefers looking at fresh flowers. [These|That|This|Those] are some white ones in a vase. I'm sitting on the floor.[This|These|That|Those]is a bed next to me. Can you guess my favourite pet? It's a cat. His name is Tom. Tom likes sleeping on[those|these|that |this]blue mat next to me.