 Complete the following phrase:  Over the course of several months, the FBI listened to Zazis phone conversations. In August 2009, the FBI overheard him speaking about mixing chemical substances. It learned that in July and August 2009 he and his three associates were buying large quantities of hydrogen peroxide and acetone products from beauty supply stores around Denver, Colorado. Workers at the Beauty Supply Warehouse in Aurora, Colorado would later tell CNN that Zazi was a regular at the store and had made several recent purchases shortly before his arrest, telling them that he had a lot of girlfriends. Hydrogen peroxide and acetone are components of triacetone triperoxide TATP; also known as acetone peroxide-based bombs. TATP was also used in the 