What is a diagnostic procedure done on the esophagus using a scope through a stoma called?

The reason that carbon monoxide is so toxic is because it:

A Is a protoplasmic poison. B. Combines with cytochrome oxidase. C. Has 200–250 times the affinity of oxygen for hemoglobin binding sites. D. Sensitizes the myocardium.

________ is a recent advancement in modern medicine and used routinely during certain forms of surgery.

A. Aseptic technique B. Anesthesia C. Robotics D. Blood transfusions