Используйте глаголы в present indefinite tense и перевести предложения:
1. They simply (to mean) they cannot satisfy everyne's wants.
2. When they say something (to be) scarce they mean that there (tobe) not enough of it.
3. Scarcity (to exist)in all countries, both and poor.
4. Very many wants (not to be) unlimited.
5.Our wants (not to be)unimited.
6. We (to see) that insome countries people are generally well off.
7.It (toseem) very strande that economists say this.