Answer:
tienes que saber cual es la pregunta
The answer is "stacks." That is the object of the phrase, and since a person is searching for something ON the shelf, they aren't searching for the shelf itself.
Well for reading the passage I will say the answer is (A).
One example of scanning is a Printer. You can scan something onto a flash drive and send it to a company, a teacher, or your friends.
<h3>I'll just remove the answer because you don't need it :/ </h3>
