- Oxygen is a kind of element
- Hydrogen is a kind of element
- So, hydrogen and oxygen are two elements

- Hydrogen and oxygen are two elements
- Water is made of hydrogen and oxygen chemically combined
- Hence, water is made of two elements

- Water is made of two elements
- A compound is made of two or more elements chemically combined
- So, water is a kind of compound

So, water is a kind of compound
[Question]A scientist combines oxygen and hydrogen to form water. This combination illustrates that water is
[Context]- Oxygen is a kind of element 
- A compound is made of two or more elements chemically combined 
- Water is made of hydrogen and oxygen chemically combined 
- Hydrogen is a kind of element