1.A need is something you have to have to survive or complete a task. A want is simply the desire for something, in many cases something to satisfy a need. You need food to survive.
2.In the field of behavioral economics, the term utility refers to the perceived value (i.e., usefulness) an individual receives when they purchase a good or service. There are four different types of utility: form, place, time, and possession utility.
3.We must help to anybody who fell in bad trouble to do our society better/
4.We speak with different people from different countries.Many nations want submarines. Economists say that utility determines 'the relationship between a consumer and a commodity'.
Utility varies between different people and between different nations. A vegetarian does not want meat, but may rate the utility of bananas very highly, while a meat-eater may prefer steak. A mountain-republic like Switzerland has little interest in submarines, while maritime nations rate them highly.
5.The production of pianos falls sharply in wartime.
The utility of a commodity is also related to the quantity which is available to the consumer. If paper is freely available, people will not be so interested in buying too much of it. If there is an excess of paper, the relative demand for paper will go down.
6 и 7 незнаю((.
2. "Stay for dinner", - we told them.
3. "I am sorry for forgetting your birthday", - apologized she.
4. "You stole my wallet", - he accused her.
5. "I will help you organize the party", - he ageed.
6. "Stay away from the water", - they warned children.
7. "I will write every week", - she promised.
8. "If you misbehave I will tell the teacher", - he threatened.
9. "I advise you to study hard for the exams", - I said.
10. "Let's go for a walk!" - she suggested.
11. "It's not my fault", - he explained.
12. "We won't open your letter", - they said.
13. "Let me help you with the housework", - she offered.
14. "You are always tired!" - he complained.
15. "Come to our party", - they said.
16. "I will call the police if you do it again", - threatened she.