A. blood circulation
B. nervous system
C. the sense of hearing
D. the height above sea-level

A. measuring the intensity of radiation
B. measuring the intensity of light
C. measuring blood pressure
D. measuring angular distances

A. 0.1%
B. 2%
C. 95%
D. 0%

A. blood platelets
B. plasma
C. red corpuscles
D. white corpuscles

A. thigh bone
B. chest tissues
C. eyes or an eye lens
D. skull

A. allergy
B. infection
C. virus
D. none of the above

A. stoppage of blood supply to tissues
B. getting suddenly frightened
C. insufficient supply of blood to the brain
D. obstruction in critical veins

A. cardiogram
B. cardiograph
C. cardiometer
D. altimeter

A. Lord Lister
B. Alexander Fleming
C. Karl Landsteiner
D. Walter Reed

A. vitamin A
B. vitamin D
C. ascorbic acid.
D. thiamine