Burning of which of the following fuels produces the least amount of carbon dioxide per unit of energy?

You arrive back in the United States after having visited a foreign country located on another continent. The customs agent stops the person in front of you and confiscates the fruit basket this person is bringing home. Being the knowledgeable person you are, you calmly explain to your enraged fellow traveler that the reason for the detainment is that the fruit basket may be

One of the problems that occurs as a consequence of chlorofluorocarbon (CFC) pollution is ________.

Small areas that exhibit exceptionally high (endemic) species diversity are referred to as

Which of the following statements about global “climate change” and its potential causes are KNOWN to be true?

Mercury is particularly hazardous to human health because

The effects of acid rain include

True or false. Removal of Pisaster starfish in the intertidal zone of Pacific Northwest (Washington) leads to an increase in diversity of other invertebrate species.

Ozone in the stratosphere is

A tree community consists of 4 maples, 3 oaks, and 1 alder. The species richness of this community is