Review the responses below; then SELECT ALL the reasons why we use scientific models.

a
Models allow exploring very small or very large systems.
b
Models help you understand complex systems.
c
Models are used when systems are too expensive, expansive or impossible to use.
d
Models are always expensive.

a

b
c

The correct options are:

a) Models allow exploring very small or very large systems.
b) Models help you understand complex systems.
c) Models are used when systems are too expensive, expansive or impossible to use.

Option d is incorrect as models are not always expensive. They can be created at various costs depending on the complexity and resources required.