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((.
I must go now. It’s too late. – Я должен идти сейчас. Уже слишком поздно.
You must find a new secretary. – Вы должны найти нового секретаря.
He must earn money for his family. – Он должен зарабатывать деньги для своей семьи.
Children must clean their room. – Дети должны убирать свою комнату (общепринятое правило).
They must be careful with this man. – Они должны быть осторожнее с этим мужчиной
I must hurry. I must not be late. – Я должен спешить.Мне нельзя опаздывать.
You must not walk on the grass. – Вы не должны ходить по траве.
must not = mustn’t (сокращение)
You mustn’t speak here. – Вам нельзя здесь разговаривать.
Students mustn’t leave the classroom before the bell rings. – Студентам не разрешается покидать класс, пока не прозвенит звонок.
You should not walk on the grass. – Вам не стоит ходить по траве.
Students ought not to leave the classroom before the bell rings. – Студентам не следует покидать класс пока не прозвенит звонок.
