Complex sentence: Chapter 3, "Poseidon and the Greeks", covers the building of the temple of Poseidon in Paestum; chapter 4, "The Romans and the Volcano", tells of the destruction of Pompeii.
Split into simpler sentences: Chapter 3, "Poseidon and the Greeks", covers the building of the temple of Poseidon in Paestum. Chapter 4, "The Romans and the Volcano", tells of the destruction of Pompeii.