Martha knows that her memory is not what it used to be, so she makes up rhymes for items that are especially important to remember. martha is using a(n) technique.

Mnemonic technique is the correct answer.

Mnemonic is a very effective memory technique that helps people to remember important words, a list of things or larger pieces of information through association. Martha uses this simple technique by rhyming items, but she could also use humor, exaggeration, and symbols to help her learn and enhance memory.  

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.        

your answer would b. the missisipi river

hope i you : )