Correct Answer is A. They were able to increase their productivity due to the popularity of tractors.
Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension.
Explanation:
Answer;
-PET scan
A PET scan uses radioactive markers in the blood to monitor blood flow and metabolic activity via x-ray
Explanation;
-A positron emission tomography (PET) scan is an imaging test that helps reveal how the tissues and organs are functioning. A PET scan uses a radioactive drug (tracer) to show this activity. This scan can sometimes detect disease before it shows up on other imaging tests.
-A PET scan is used to diagnose certain health conditions, to plan treatment, to find out how an existing condition is developing, and to see how effective a treatment is.
-In a PET scan, a machine detects radiation that is emitted by a radiotracer. A radiotracer consists of radioactive material that is tagged to a natural chemical, such as glucose.