Imagine that you are researching the reconstruction time period in u. s. history. your teacher tells you that you are allowed to use sources from the internet. which of the following would most likely be a valid source that you could use in your research?

an online article from the Journal of Southern History

Explanation:

When doing research, it is important to understand how to identify a valid source. The Internet has a wealth of information, but not all of it can be considered valid. Of the answer choices listed here, the best source would be an online article from a historical journal. Journals such as the Journal of Southern History contain articles written by historians who have thoroughly researched their subjects. These articles are also reviewed and edited by other experts on the subject matter. Sources like blogs or free online encyclopedias are not always written and edited by subject experts, so the information they contain might not be valid. For this reason, these sources should be avoided when doing research.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)