An example  of a molecule that uses facilitated diffusion to enter the cell is oxygen starch glucose carbon dioxide

Facilitated diffusion is a type of passive transport that requires specific proteins to help molecules move across the cell membrane. It typically occurs for larger or polar molecules that cannot easily pass through the lipid bilayer of the cell membrane.

In the options provided:

1. Oxygen and carbon dioxide are small nonpolar molecules that can diffuse freely across the cell membrane without the help of a protein.
2. Starch is a large polysaccharide that cannot enter the cell directly; it must be broken down into smaller molecules before it can be absorbed.
3. Glucose is a polar molecule that requires transport proteins (such as glucose transporters) to help it cross the cell membrane via facilitated diffusion.

Final Answer

The correct example of a molecule that uses facilitated diffusion to enter the cell is glucose.