Many ________ are responsible for causing ________ pollution. Petroleum ________ are a major source of ________ pollutants like ________ and ________.
(sulphur dioxide, refineries, industries, nitrogen dioxide, gaseous, liquid, people, air).

Explanation

To fill in the blanks in the given question, we can follow these steps:

1. **Identify the first blank**: The sentence starts with "Many ________ are responsible for causing ________ pollution." We need a term that represents a group of entities that can cause pollution. The most fitting word here is "industries."

**Hint**: Think about groups or sectors that contribute to pollution.

2. **Identify the second blank**: The next part of the sentence is asking for the type of pollution caused by these entities. Given the context of the question, "air" is the most appropriate choice since industries are known for contributing to air pollution.

...