2. (a) European countries like Germany get a lot of natural gas from Russia. If Russia stops supplying natural gas to Europe due to the war in Ukraine, then will this represent a shift of the supply curve of natural gas or a movement along the supply curve of natural gas. (b) What will happen to the market equilibrium price of natural gas in Europe if Russia stops supplying natural gas to Europe? Please explain. 3. Since all residents of the United States can get the Covid 19 vaccine at no cost, the price for consumers is effectively zero. At a zero price there should be large shortage with high demand and low supply. However, we know that there is no shortage and in fact there is a surplus of vaccines. Why is supply of vaccines higher than a zero price would indicate, and why is demand for vaccines lower than a zero price would indicate? Please give an explanation.