What city in the mongol empire was conquered 4 years after beijing was conquered?

That city would be otrar
Before entering otrar, Gengis khan gave a warning to the city leader to surrender and bow down to is Rule or all of the citizens were going to be massacred. Otrar initially saw that as an empty threat but one year later Gengis Khan proved that he never threw a threat that he couldn't accomplish.

I'm taking that test i will let you know!