While testing amylase activity, john uses a buffer of ph 6 and substrate starch. he incubates them at 104ºf (40ºc). all the tubes show glucose formation, except one, which had no starch solution. why did this happen?

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.