Explain each answer. The answers are short but there must be explanation for each answer. Long explanations.

1) Alfred Marshal, famous economist contributes mainly in the field of

2) Who firstly introduced "Liquidity of Preference theory"?

3) The term water in economics deals with ____________

4) The term "Technology "is defined in economics as _________

5) In which theory "Marginal Productivity theory "deals with?

6) Price determination is studied traditionally. What is it called?

7) The word 'Invisible hand 'in economics is defined as

8) To Influence consumers a producer, have to spend money. This is an example of

9) Whose opinion is 'Rent is a creation of value' not of wealth?

10) The concept" Representative Firm" is introduced by __________

11) The book "The social framework" is written by

12) "Theory of income determination" is introduced by _______ in its modern form.