When air is contaminated by ________ substances which have a ________ effect on both the ________ and ________, it is referred to as ________.
(air pollution, harmful, living, unwanted, non-living, pollutants)

Explanation

To complete the statement correctly, we need to fill in the blanks with the appropriate words from the given options. Let's break it down step by step.

### Step-by-Step Solution:

1. **Identify the context of the statement**: The statement discusses air contamination and its effects on different entities.

2. **Fill in the first blank**: The first blank requires a term that describes substances that contaminate the air. The most suitable word from the options is "unwanted."
- **First blank**: unwanted
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