physioEX 8.0 review sheet exersice 7

can someone plz help me with these review questions
11.) what condition does opening the valve stimulate?
13.)what happen to the total flow when the valve was opened?
16.)what was the value of the Pco2 with rebreathing ? explain any difference.
17.)what happen to the rate of respirations with rebreathing?why do you think it happened?
25.)describe the effect the inhaler medication had on the FVC and FEV1
26.)did the values return to normal?why
27.)during moderate exercise breathing which volumrs changed the most?
28.)during heavyexerise breathing which volumes changed the most?