Erin helps some students with their ebola model. (53 K)

Bob2 looks on as stundents busily model. (59 K)

One students takes notes as Bob2 explains 'OEDs.' (52 K)

Bob2's 'stupid rope trick' shows how you can observe better. (46 K)

Bob2 tells us what we need to know about OEDs. (29 K)

A student waits to ask Erin a question. (58 K)