"Diseconomies of scale" occur in ( ) A: the long run, but not the short run. B: the short run, but not the long run. C: both the short run and the long run. D: neither the short run nor the long run.

In the short run,____________

The short run is a period of time so short that:

Two interpretations of the IS-LM model are that the model explains：（ ） A: the short-run quantity theory of income, or the short-run Fisher effect. B: changes in government spending and taxes, or the determination of the supply of real money balances. C: the determination of investment and saving, or what shifts the liquidity preference schedule. D: the determination of income in the short run when prices are fixed, or what shifts the aggregate demand curve.

It pays ______ to buy goods of high quality. A: in the long run B: in the short run C: at a run D: on the run

The short run industry supply curve can be found by horizontally summing the short run supply curves of all the individual firms in the industry.

Monetary policy affects employment A: only in the long run. B: only in the short run. C: in both the long run and the short run. D: in neither the long run nor the short run.

Most economists believe that classical theory describes the world in the short run but not in the long run

Which of the following is accurate? A: Monetary policy is neutral in both the short run and the long run. B: Though monetary policy is neutral in the long run, it may have effects on real variables in the short run. C: Monetary policy has profound effects on real variables in both the short run and the long run. D: Monetary policy has profound effects on real variables in the long run, but is neutral in the short run.

But for her help, they ___ over the mountain in such a short time. A: couldn't have run B: had not run C: have not run D: could have run