Explanations and sources please. Thank you.

1) The book 'Economics of Imperfect Competition' was written by

2) In 1946, W. W. Leontief was appointed as an Economics professor at a university. Give the name of the university.

3) In which year did Paul A Samuelson get the Nobel Prize in Economics?

4) The number of economists who shared the Nobel Prize in Economics in 1990 was________.

5) The country with the highest GDP in the world is

6) The country with the lowest GDP per capita in the world is

7) The country with the highest per capita income is

8) What is the definition of 'Demand for a Commodity'?

9) What proportion of GDP does agriculture contribute in the United States?

10) The country with the highest per capita daily calorie intake is .

11) The world's most indebted country is .

12) The highest per capita energy consumer is determined to be a country with a high income. Make a mention of the country.

13) What is the name of the country where the whole population lives in cities?

14) The world's lowest death rate is in

15) A developed country has the greatest infant mortality rate. Make a mention of the country.

16) 'A branch of science that investigates human behavior as a relationship between ends and means with multiple applications.' Which economist coined the term "economics"?

17) Japan is the country with the longest life expectancy in the world. How long do you think you'll live?

18) The most important source of assistance for third-world countries is .

19) Which country produces the most milk in the world?

20) Which country imports the most German automobiles?