The Cuyahoga River in Ohio had been so polluted that it caught fire repeatedly from 1868-1969, including a 1952 fire that resulted in nearly $1.5 million in damages. Amazingly, other rivers in the United States also caught fire during this period. Why didn’t federal laws limiting pollution of rivers and streams prevent this pollution and these fires?

________ involves meeting the needs of the present without sacrificing the ability of future generations to meet their own needs.

European rabbits were introduced into Australia and quickly spread, reproduced, and became a terrible pest. They eat up to $600 million worth of food and pasture crops annually, and have damaged the populations of many native plants and the populations of animals that eat the plants. Twice in the past 50 years, rabbit diseases have been introduced to try to control the population, with some success. This is a case where ________.

The ________ system of timber harvesting involves leaving small numbers of mature trees in place to provide shelter for seedlings as they grow.

Earthquakes result from ________.

Read the following scenario and answer the question below. Burning fossil fuels and their derivatives produces, among other things, harmful pollutants such as particulates, acid rain-producing sulfur and nitrogen oxides, and carbon oxides. These air pollutants threaten ecosystems all over the world, and high carbon dioxide levels contribute to global warming. Furthermore, fossils fuels have a limited supply. The market price of fossil fuels, especially crude oil, has continued to rise in recent years. Despite this, Americans continue to consume fossil fuels at alarming rates and rely upon them for most of energy needs. At various times, the federal government has considered mandating higher fuel efficiency standards for American vehicles as a possible solution to this environmental energy crisis. Most auto manufacturers, however, are opposed to the imposition of standards. What factor might lead to more political support for higher fuel-efficiency standards?

Read the following scenario and answer the question below. The western United States contains a series of tall mountain ranges that also extend far down into Mexico. Two of the largest of these ranges are the Rockies and the Sierra Madres, but they are all part of the same mountain-building event that occurred many millions of years ago, and they all have similar features. Much of the vegetation on these mountaintops is the same, or very similar, and they are often referred to as the “Sky Islands” because of their similarity to each other and their isolation from the lower, drier areas surrounding them. Large predators and omnivores, such as mountain lions and bears, roam these mountain ranges. Which of the following statements is TRUE?

Biodiversity is important because of ___________________, which is searching for organisms that might provide new drugs, medicines, foods, or other valuable products.

What is the greatest contributing factor in the loss of polar bears in arctic areas?

Read the following scenario and answer the question below.  In 1906, President Theodore Roosevelt created the Grand Canyon National Game Preserve on the Kaibab Plateau in northern Arizona. Between 1907 and 1923, cattle grazing was greatly reduced, mule deer hunting was eliminated, and predators were killed. Over 800 cougars, 20 wolves (most had already been killed in the 1800s), and 7000 coyotes were trapped or shot. In response, the mule deer herd began to increase: By 1915, deer numbers were estimated at 25,000; 50,000 by 1920; and 100,000 by 1923. The removal of the livestock and predators, and the cessation of hunting in 1907 ________.