Answer:
Step-by-step explanation:
Basically anything your teacher gives you and you know is reliable.
Reference materials are various sources that provide background information or quick facts on any given topic.
For example, culture grams is an example of a reference material because you can go on that website and receive accurate information.
Wikipedia can count as a reference material but it isn't reliable. People can go in to edit what is being said on Wikipedia; but in general, Wikipedia is a reference material.