Не могу справиться с 4 you have 20 to buy some gfts for your family. write what you would like to buy. use this, that, these,those

I want to buy this dog for my mother.
But I think that one is more beautiful.
This vase is brilliant .I want to buy this for my granny.
That cup is very nice. I am going to buy that.
These socks will be great to my father.
I think those books will be interesting to me.