The source of the earth's magnetic field is the exosphere.

a. True

b. False

Are lightning fatalities more frequent, less frequent, or at the same rate today as they were in the 1950s? Select one: a. more frequent b. less frequent c. same rate d.

When did the worldwide response to ozone depletion begin? Select one: a. 1940s and 1950s b. 1960s and 1970s c. 1970s and 1980s d. 1980s and 1990s

If there are 1030 grains of sand on Playa de Sonrisa, how many of these grains of sand are submerged by the ocean at least once a day?

Approximately what per cent does Central America contribute to the total amount of carbon dioxide produced in the world

1. The number and location of bones of many fossil vertebrates are similar to those in living vertebrates. This is evidence in support of which of the following concepts?

The lengths of the worms in inches are listed here

Scientists who study rock formations in caves describe some of the formations as "living rock" because, under certain conditions, they increase in size.

Pieces of ice that break off of a glacier and drift out to open sea are:

Landslides, mudflow, slump and creep are all examples of a. constructive force c. mass movement b. deconstructive force d. none of the above

Which of these protects Earth from harmful radiation when in the stratosphere but is a pollutant at lower altitudes? carbon oxygen ozone hydrogen