Question

the british thought the taxes were fair.
the tax money helped protect the colonies.
revise your work. which joining word helps tell why or give a reason?
the british thought the taxes were fair, the tax money helped protect the colonies.

Explanation:

The second sentence gives the reason why the British thought the taxes were fair. The joining word "because" is used to introduce a reason or explanation. So we use "because" to connect the two sentences to show the causal relationship.

Answer:

The British thought the taxes were fair, because the tax money helped protect the colonies.