A) 1 month; 4 years B) 6 months; 3 years C) 1 year; 4 years D) 18 months; 3 years Answer: C Topic: Business Cycle Patterns Skill: Recognition 4) According to the National Bureau of Economic Research, since 1920 the average length of reces-sions has been approximately A) one year. B) a year and a half.C) two years.) 1 month; 4 years B) 6 months; 3 years C) 1 year; 4 years D) 18 months; 3 years Answer: C Topic: Business Cycle Patterns Skill: Recognition 4) According to the National Bureau of Economic Research, since 1920 the average length of reces-sions has been approximately A) one year. B) a year and a half. C) two years.
Lungs and Respiratory System of the Chest The respiratory system of the upper abdomen and chest includes the structures involved in the vital delivery of atmospheric air and the exchange of gases between the body and atmospheric air.
The lungs are located in the chest on either sides of the heart. The primary causeâ¦. 2  Just Breathe: Studies in Pulmonary Function The lungs move oxygen into the body and carbon dioxide out into the air. 3  Pulmonary function studies are conducted to measure the effectiveness of your lung function. 4  Here is â¦.