Variations of bowling have existed for centuries, but a standard form of the game wasn't established until various regional bowling clubs formed the American Bowling. What sentence is this
Complex
Simple
Compound
Compound complex

Complex

Explanation:

Complex sentence is a sentence that contains an independent clause and at least one dependent clause.

The independent clauses can stand alone and give a full thought while the dependent clause cannot give a complete thought.

From the answer, we discover that:

"Variations of bowling have existed for centuries" is an independent clause and makes a complete thought while

"...but a standard form of the game wasn't  established until various regional bowling clubs formed the American Bowling." is the dependent clause which gives an incomplete thought.

The above answer is correct.

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