1. ri.2 part a: which statement identifies the central idea of the text?
a. experts have spent time researching how different the teenage brain is from adults’ brains, when they are actually more similar than different.
b. teenagers often engage in risky behavior to fulfill the narrative they have been told about how teenagers are supposed to behave.
c. explanations for why teenagers engage in risky behavior have been overly focused on brain development, rather than their natural need to explore the world.
d. teenagers’ risky behavior is influenced by the combined effects of their hormone levels and their brain development.

answer; i believe that the correct answer is (tabula rasa);

experiments.

surveys.

questionnaires.

interviews.

case studies.

participant and non-participant observation.

observational trials.

studies using the delphi method.

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)

answer; (b) knowledge based summaries of our beliefs and feeling about the self in particular domains;