Answer:
B..........................
Explanation:
<span>The amount of goods and services produced by an economy divided by the amount of resources used to make those goods and services, measures economic D. productivity.</span>
Answer: White blood cells form to fight off cell infections.
Explanation:
1. Your body produces white blood cells which fight against infected cells, depends on what type of cell it is and how infected it is.
2. The immune response to a viral infection is primarily generated by a type of white blood cell called lymphocytes; cells that are mostly localized in ‘lymphoid tissues’ such as the lymph nodes or tonsils. However, the number of lymphocytes that can recognize and react against any individual type of virus is initially very small. This is particularly true for a novel virus such as SARS-CoV-2, which people have never encountered before. In order to produce an effective immune response, the small number of lymphocytes that can recognize a virus must become more abundant. Even though lymphocytes proliferate quickly it still takes several days before there are sufficient cells available to fight back against the infection. During this period the virus may also be spreading rapidly, so there is a race between the virus and the immune system that may determine the final outcome, in terms of recovery.
Answer: Pulmonary artery
Explanation:
All arteries carry blood away from the heart while all veins carry blood to the heart. With the exception of pulmonary artery, all arteries contain oxygenated blood while all veins except pulmonary vein contain deoxygenated blood.
Thus, pulmonary artery is the answer
