1.

Required characteristics are as below:

#) Very high population growth: the developing countries having rapid growth in population reduces GDP per capita (= GDP / Number of population). Such reduction makes them low-income countries.

#) illiteracy: most of the people there are illiterate.

#) poor health: average health standards are not up to the mark. People are not serious about it although it increases productivity of labors.

#) severe unemployment: the rate of unemployment is very high there and this is because of rapid population.

#) agricultural dependency: most of the people there are dependent on agricultural activities. It makes a limitation of their income. High-income countries, on the other hand, are mostly dependent on industrial activities.

2.

Expansionary policies are ideal in COVID-19 issue.

There may be expansionary monetary policies, like the reduction in bank interest rate, purchase of government bonds, and lowering down required reserve ratio in commercial banks; all these are done by the central bank of the country (like Federal Reserve in the USA).

The government of the country (like Federal Government in the USA) may take expansionary fiscal policies, like purchasing bonds from open market, reduction in tax rates, and the increase in government spending.

All these increase money supply in the economy, which boost up economic activities and can make it stable. More than one policy can be taken at a time.