Diffusion and osmosis question

In your large intestine, the water from the food you have eaten needs to be kept in the body to prevent dehydration. Therefore the high concentration of water in feces needs to be moved into the surrounding cells. Is this osmosis? Explain your answer.

When you are exercising, your muscle cells use sugar to produce energy. To provide more sugar to these muscle cells, your body releases a hormone that will add sugar to your bloodstream. The sugar needs to move from the bloodstream to the muscle cells, but sugar molecules are fairly large molecules. What type of cell transport mechanism will likely be used? Provide reasons for your choice.

When you breathe, the gases oxygen (O2) and carbon dioxide (CO2) need to be transferred between your blood and your lung cells. Blood coming to the lungs is high in CO2 and low in O2. The cells in your lungs are high in O2 and low in CO2. What transport mechanism will be used to transfer CO2 to the lungs and O2 to the blood?