An engineer tests three new ceramic parts, each of which could potentially replace a steel part inside an automotive engine. The three parts, identical in size, are each made of a different ceramic compound. The parts are heated to the same temperature and placed under the same stress loads. At the end of the test, the engineer concludes Part B is the best for the job. What was the independent variable in this test? Select one:

a. dimensions of the parts

b. temperatures to which the parts were heated

c. the engine used to test the parts

d. the composition of the parts

Which statement correctly describes a way that mutations increase the likelihood that a species will survive in a changing environment

Anurse is preparing to administer ampicillin 500 mg in 50 ml of dextrose 5% in water (d5w) to infuse over 15 min. the drop factor of the manual iv tubing is 10 gtt/ml. the nurse should set the manual iv infusion to deliver how many gtt/min? (round the answer to the nearest whole number. use a leading zero if it applies. do not use a trailing zero.)

Juan and carol were studying invertebrates in biology. they knew that segmented or earth worms preferred a dark, moist habitat. during this lab, they would be investigating the responses of organisms called planaria or dugesia tigrina. these were simple flatworms that still had a one-way digestive system and a very simple nervous system. juan and carol placed the planaria in a petri dish containing cool, distilled water that was partially covered with black paper. they shined a light on the dish. next, they removed the paper and placed a small amount of chicken liver at one end of the dish. they added a few large salt crystals to the water. finally, they added drops of hot water to the cool water in the petri dish. their results can be seen in the data table. according to their experiment, all but one conclusion is valid.