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The Great Rift Valley is a

The Great Rift Valley is a series of contiguous geographic trenches.

Explanation:

I HOPE THIS HELPS

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

answer: musical connotation

leonard b. meyer (1918-2007) was an american composer, author and philosopher. his work emotion and meaning in music is perhaps the first major treatise on music. it is a philosophical and psychological work, greatly influenced by koffka (one of the major proponents of gestalt psychology). his work deals with the problem of musical meaning and musical communication.