The correct answer is - it's mass.
Jupiter is the biggest planet in our Solar System, but only the biggest, also it has the biggest mass by far from all the planets. Because of its very big mass Jupiter has a very strong gravitational pull. The strong gravitational pull contributes to the attraction and keeping of lots of bodies that can not escape it, instead they revolve around the planet. These objects, or space bodies, that the gravitational pull of the planet managed to trap, became the moons, or rather natural satellites, of Jupiter.
Not quite sure what you're asking, but erosion and deposition do create land forms. For example: erosion along the coastline may result in the formations of arches, stacks, stumps, wave cut platforms, caves, etc. Deposition, different amount of it and in certain areas, under the influence of either destructive or constructive waves, will form beaches - ones with a lot of beach, through a lot of deposition, or slopes beaches where destructive waves have crashed upon the beach. Hope this is what you're looking for.
The difference between a dry climate and a tropical climate is that the dry climate as you know is dry and the tropical climate is moist and wet, the compare is tropical wet climates receive much more rain than tropical dry climates do. However, the term “tropical wet and dry climate” actually refers to a single type of climate. Tropical dry climates occur in deserts, while tropical wet climates usually occur along the rainforest belt.
I'm thinking about India or South Africa, but I am pretty sure it is India because South Africa had Mandela for a really long time.
