What did the pueblo people use to grow crops in a dry land

With the sedentary lifestyle, Pueblo people depended on farming to sustain their families.

They used to grow crops in the dry land because they developed a technique to conserve water. They used Pumice -a derived of volcanic rock- because it served like a sponge. It could absorb water -like a storage that retained the liquid- and released over time.

Another technique was to built small depressions in the land surrounded by a  wall for the conservation of the seeds to be planted.

With these techniques, they seeded vegetables like corn because is a plant that tolerates the sun and grows tall.

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; i believe the correct answer is (117);