One reason HIV/AIDS is serious is a. the virus survives well in the environment.
b. it is transmitted through casual contact.
c. many infected people do not know they are infected.
d. people do not know how to prevent it.

help please

Which of the following are considered general purposes of performing pulmonary function tests (pfts)? 1. the functional status of the lungs 2. the diffusion characteristics of the alveolar-capillary membrane 3. how much and how fast gas can be moved into and out of the lungs 4. the specific diagnosis of pulmonary disease