Asociety is considered sustainable if it:
a. requires that people who use more resources pay higher taxes and fees than those who use fewer resources.
b. obtains environmental goods from another country.
c. recognizes the limits of the environment and looks for alternatives to using up natural resources.
d. uses other countries' resources before creating artificial resources.

Sustainable development of a society means that resources are used wisely enough and will still be present for the use of the future generation. If choice A is correct, people would have the power to exploit resources as long as they have money. If choice B is correct, a country would be able to sustain itself in the expense of another country, which is morally wrong. If choice D is correct, then people in the future would only have artificial resources in their hands which would create a lot of problems in regards health, economy, etc. Therefore, all these three choices are wrong.

A society is consired sustainable if it (c) recognizes the limits of the environment and looks for alternatives to using up natural resources.

The option that best describes the main idea of the fourth paragraph, which begins "We dare not to," in John F. Kennedy's Inaugural Address is C. The new generation of United States' citizens will continue to fight for freedom. President Kennedy states that, as heirs of the revolution of the forefathers, the new generation will continue to fight for the rights that do not come from the state but from God.