The rough sections of the Nile that were impassable to boats were called . A. rapids B. deltas C. cataracts D. whirlpools Please select the best answer from the choices provided A B C D

C. Cataracts.

The rough sections of the Nile that were impassable to boats were called cataracts.

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answer c

Explanation:

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.        

step 1. boil eggs

step 2.eat eggs

step 3. get your hot poonts ready