Zebra mussels, a nuisance when they clog the intake pipes of nuclear power plants and water plants along the Great Lakes, have some redeeming qualities. █████ ███ ███████ ████ ███████████ ██ █████ ████ ████ ██████ ████ ███ █████ ████ ██████ ██ █████ ████ ██ █████ ███████ █████████ ██ ███ █████████ ███████ ██ ████████ ██████ █████████████ ███████ █████ ████████ ████ ████████ ████ █████████ ███████
Our approach to stimuli in MSS questions is to develop a big picture understanding of the subject matter, while bearing in mind that the answer could still come from seemingly unimportant details. Here’s a low-res summary of the claims in this stimulus:
Zebra mussels are annoying when they clog intake pipes, but they’re good when they eat algae. In fact, you can hang a bag of Zebra mussels by a discharge pipe and they’ll soak up hazardous waste and improve water quality.
The answer really could come from anywhere – there are no obvious “link this up with that” inferences, so you should feel comfortable relying fully on process of elimination as you move into the answers.
Analysis by MichaelWright
Which one of the following ██ ████ ████████ █████████ ██ ███ █████ ██ ███ ██████████ ██████ ██ ████ ███ █████
Zebra mussels arrived ██ ███ █████ █████ ██ █████████████ ██████████ ████ █████ ████ ████ ██ ███████ ███████ ██████ ███ ███████ ██████████ ███ ██████ ███████ ██ ██████
If the mussels ██████ ██ █████ ██ ███ ███████████ █████ █████ ██████ █████ ███████ ███ █████ ███ █ ██████████████ █████████ ████ ████████ ████ █████████ █████ ███ ███████ ███ ██████████ ███ ████ ███ ███ █████ ████████ ███ ██████
There is no ██████████ █████ █████████ ███ ████████ ██████ █████ ██ ████████ ███ ███████ ████ █████
The algae on █████ ███ ███████ ████ ██████ ██ ███ ████████ ██ ███ ████████ ██████████ ████ ███ ██████ █████ ██ ███████ █████ ██████ ███ █████ ███████
Any hazardous waste ███ ███████ ██████ ████ ██████████████ █████████ ████ ██████ ██ ███ ████████ ██ ████ ██ ███ █████████ ███ ███ ████ ████ ████ ██ ████████ ██ █████████ ██████