Answer 1

1. Most of the world's tropical deserts are located in the western margins of continents in the subtropics because the prevailing winds in the tropics are Tropical Easterly Winds. The Tropical Easterly Winds become dry by the time they reach the western margins of the continents and so they bring no rainfall.
2. There is no continent without a desert region. Despite its thick ice, Antarctica is classified as a desert because very little moisture falls from the sky.