In lungs, oxygen diffuses from air to venous blood because the partial pressure of oxygen in the lung air is .................... than the partial pressure of oxygen in the venous blood.

Explanation

To answer the question about the diffusion of oxygen in the lungs, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Partial Pressure**:
- Partial pressure refers to the pressure exerted by a single type of gas in a mixture of gases. In the context of the lungs, we are specifically looking at the partial pressure of oxygen (O2).

2. **Gas Diffusion Principle**:
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