ПОМОГИТЕ ПОЖАЛУЙСТА, КОМУ НЕ СЛОЖНО!!!!

Вставьте в предложения следующие слова и словосочетания в соответствующей форме:
choice, to obtain (2), number, that is, within (2), to maintain, constant, rather than, per (4), provided, to result in, to assume, to choose
1. We assume that the consumer prefers to have more of a good….. less.
2… the good whose price has risen is a normal good, the economist can… that the demand for it will fall.
3. A constant level of utility is… through correct choice of goods or services that can be… at one time.
4. The lower price….. additional demand.
5. People must often make a… between two or more goods. They usually… the good with the highest utility… the limited budget, choose the cheapest good.
6. Income is usually counted… year, but sometimes also… month or even… week.
7. The man having a credit card has to pay… a certain… of days for everything that he has bought with its help during the month.
8. We do not assume that… acre productivity will remain… as modern agricultural technology allows farmers to… better results.