Complex sentence: Invented in ancient Babylon in 4500 B.C. and continually developed since then, the most common household toasting appliances are now the pop-up toaster and the toaster oven which have been known to produce PCP as an unintentional byproduct.
Split into simpler sentences: Invented in ancient Babylon in 4500 B.C. and continually developed since then. The most common household toasting appliances are now the pop-up toaster and the toaster oven, Both of which have been known to produce PCP as an unintentional byproduct.