What is a kremlin? a) a tall bell tower used to call russian citizens to prayer b) a multi-domed cathedral at the heart of a russian city c) a walled fortress designed to protect a russian city d) a place where the tsar and his family resided

The Kremlin is where Putin currently lives. It is a palace and several assisting buildings, with a wall around the whole thing. The Multi-domed building is St. Basil's Cathedral. The Tsar was probably in another palace,  on the run from Rasputin.

disequilibrium means that either supply is greater than the demand for an available good, or that the demand for a product outstrips the available supply. it implies that the price for a is either too low creating large demand, or too high creating a large surplus of supply.

the effect of the ming leaders banning ships with more than two masts was that there was no further construction of ships masts, because there was a surplus. ming emperors disallowed foreign exploration