Please help me to answer these questions, thanks.

20. Solutions to the Great Depression favored by Classical economists included all of the following except: a) government should hire unemployed workers to build roads and bridges. b) government should stop passing legislation that held up wages and prices. c) government should let market forces operate unimpeded. government should break up labor unions. 21. Which of the following was not one of Keynes' explanations of the Great Depression? a) The economy could get stuck in a low-income, low-output, high unemployment rut. b) The financial sector did not translate savings into investment fast enough. c) The level of savings did not determine the level of investment. d) The aggregate real wage was too high. 22. Which of the following is not one of Keynes' beliefs about the macro economy? a) The economy sometimes needs help or assistance to reach its potential income/output level. b) The forces pushing the economy from its short run equilibrium income to its potential income level could be weak. c) If for some reason people stopped buying, firms would decrease their prices and people would then buy more. d) Before a long run equilibrium potential income level is reached, short run forces would push the economy away from this equilibrium. 23. In the AS/AD Model, the short run aggregate supply curve, the aggregate demand curve, and the long run aggregate supply curve are based upon: a) the principle of substitution. b) the principle of opportunity cost. c) the relationship between a single good and its price. d) the relationship between the price level and total output in the entire economy. 24. The wealth effect, the interest rate effect, and the international effect cause the AD Curve to: a) shift to the right. b) shift to the left. c) slope downward. d) slope upward