#165 Bees' Die-off

It sounds like something out of a science fiction movie - or nightmare millions of honeybees ___ dying off, their bodies never found. Scientists have ___ the phenomenon 'Colony Collapse Disorder', but they aren't ___ on the reason. Theories abound as to the ___ of the mass die-off, ranging from the unlikely (cellphones affecting bees navigational abilities) to the more ___ though still debated (widespread pesticide use).