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 circulatory system has a close interrelationship with the respiratory system. The main organ of the respiratory system is the lungs. The diaphragm is a muscle located underneath the heart and lungs that contracts to pull air into the lungs and relaxes to force air out of the lungs.When the air enters the lungs, it travels through the bronchi to tiny air sacs called alveoli.here are three types of blood vessels: arteries, veins and capillaries. The heart is an organ made of cardiac muscle and it acts like a pump. The muscles of the heart contract and pump blood away from the heart (through the aorta) and to the tissues of the body.