Dialogue:

M: Did you watch the TV special about barnacles last night?

W: No, I missed it. What did you learn about them?

M: That they glue themselves to rocks in the ocean, shortly after birth. They also stay in the same place forever.

W: Right, have you ever tried removing one of those things? It would be easier to chip the rock away than to get the barnacles off.

M: Exactly, and that's why scientists are trying to figure out what the barnacles glue is made of. It's considered one of the strongest adhesives in nature.

W: And it would have the advantage of being able to work on wet surfaces too.

M: Precisely, and because it's natural protein, it probably wouldn't be harmful to people like so many synthetic glues in use today.

W: Think of all the ways doctors and dentists could use such a glue, mending broken bones, fasting false teeth.

M: There could be countless uses. Scientists hope to learn soon exactly how the glue is made, so that people can make use of it.

Question: How many uses about such a glue are mentioned in the dialogue? 

- Two.

- There.

- Only one.


Two.