Teacher:In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. There are several possible answers, you'll need to choose the proper one. Carefully read the given text, pay special attention to the marked number, think about what (unwritten) information the marked number holds inside, choose the most adequate word(s) from the optional answers. If none of them seems right to you, there's also an option for other. If your answer is "REFERENCE", also write the reference entity, otherwise write the implicit option name. Options to choose from are:
REFERENCE: Some object which is being mentioned in the text before or after the target number. The reference answer has a higher priority than any other. If both Reference and another answer are possible, prioritize the Reference.
YEAR: Describing a calendric year
AGE: Describing someone's age
CURRENCY: Reference to some monetary value e.g dollar, euro etc.
PEOPLE: Describing a single/plural persons
TIME: Describing a time of the day. Usually you can add the word o'clock after those numbers.
OTHER: Some other option, which isn't listed here.
Teacher: Now, understand the problem? Solve this instance: Atlan:  So , how soon can this be fitted to our space choppers ?
Dr. Plaxton: It ca n't .
Atlan: Why not ?
Dr. Plaxton: Because this is the only one .
Atlan: So build more ! We 've provided you with enough raw material to build _ five hundred _ !
Dr. Plaxton: I am a scientist , not a production engineer ! And the other reason why this ca n't be fitted to your space choppers is , quite simply , it * wo n't * fit .
Atlan: Why not ?
Dr. Plaxton: Because the only way to increase the power was to increase the size of the photon generator chambers . This drive was intended to be installed in a real spacecraft , not in toys driven by a bunch of murderous psychopaths .
Atlan: Our agreement ...
Dr. Plaxton: * Our agreement * was that you provide me with the resources to continue with my work ! Well , that 's exactly what I have done .
Atlan: You
Atlan: will start modification work on the spacedrive * now * , Doctor Plaxton . If you refuse , I will tell the Space Rats that you are depriving them of speed , and I will let them deal with you ... in their own fashion .
Student:
OTHER