The patient, a 12-year-old boy, shows several areas of tooth decay: #3 mesial, #12 occlusal, #20 occlusal, and #30 on the occlusal and buccal surfaces. His mother expresses concern about the amount of decay and asks the dental assistant what can be done to prevent more problems. How should the dental assistant respond?

affects the water bodies: excessive use of fertilizers causes eutrophication. the fertilizers which are used on plants affect the quality of land on which it is used, further causing erosion of soil. the fertilizers used on plants contain harmful chemical fumes which affect the environment.

answerblank(1); ecological; blank(2); evolutionary;

reflection is the bouncing back of a propagating wave when it encounters a barrier; usually shows an image of the source of light wave

1) bounces back from an opaque material

2) bounces back from the boundary

3) seen in mirrors

refraction is the bending of a propagating wave having a shift of direction as it passes through different media; usually seen in lenses to magnify or lessen

1) passes through a prism

2) moves from one medium to another

3) seen in lenses