How does the respitatory system work with the muscular system? A: Filters out waste from food and pushes it through intestines and out the body (and you know how and where it gets out
B: Respiratory System and the Muscles of Inhalation and Exhalation.
C: It doesn't
D: Supplies oxygen to the blood and removes carbon dioxide.
Anyone help please I’m failing :(

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.