__________ are longer-term exposures, typically a month or more, of a low dose with decreased intensity

The acromioclavicular (AC) joint contributes to shoulder elevation ____________________

a. between 30 ° and 90 ° of abduction when tension on the trapezoid component of the coracoclavicular ligament produces a posterior rotation of the clavicle b. after 90 ° of shoulder abduction and until all scapulothoracic motion is taken up c. between 30 ° and 90 ° of abduction when anterior rotation of the clavicle allows for 30 ° of scapular upward rotation d. after 60 ° of abduction

The physician asks the respiratory therapist to set a mechanically ventilated patient's PEEP at an optimal level. The PEEP level is optimal when

A. PEEP levels are less than 18 cm H2O. B. PaO2 is 60 torr or greater. C. Oxygen delivery to the tissues is maximal. D. C(a-v)O2 is decreasing.