求微分方程y"＋y=cosx的通解．

A、the natural rate of unemployment.

B、cyclical unemployment.

C、structural unemployment.

D、frictional unemployment.

A. There is a strong association between drug use and crime.

B. Drug abuse is a major cause of unemployment.

C. There are great economic losses because of drug abuse.

D. Drug dependence takes a significant toll in terms of personal health and safety. .

The unemployment due to economic recession should be considered as ______.

A．frictional unemployment.

B．structural unemployment.

C．cyclical unemployment.

D．seasonal unemployment.

A、a lower real wage and a rise in unemployment.

B、a lower real wage and no change in unemployment.

C、a lower real wage and less unemployment.

D、no change in real wage or in unemployment.

Which of the following is clearly the author's own opinion？

A．The lesser of the two evils is not deflation but inflation.

B．People's income is influenced by both inflation and deflation.

C．Investment is good in times of deflation and unemployment.

D．Private and public investment can cause inflation during deflation.

Which of the following is clearly the author's own opinion？

A．The lesser of the two evils is not deflation but inflation.

B．People's income is influenced by both inflation and deflation.

C．Investment is good in times of deflation and unemployment.

D．Private and public investment can cause inflation during deflation.

Which of the following is clearly the author's own opinion？

A．The lesser of the two evils is not deflation but inflation.

B．People's income is influenced by both inflation and deflation.

C．Investment is good in times of deflation and unemployment.

D．Private and public investment can cause inflation during deflation.