Answer:
The first sentence
Explanation:
The rest of the sentences have conjunctions like 'but' and 'because'. They're connecting two sentences together with a comma. The first one is one simple sentence with no commas or conjunctions. A conjunction is a word that connects two sentences to make a compound sentence.
1.the heads on Easter island and how they move
2. how the pyramids were built
3. how the temperature of the earth is changing
