Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Spitzer Space Telescope Survey of the Orion A & B Molecular Clouds -
  Part I: A Census of Dusty Young Stellar Objects and a Study of their Mid-IR
  Variability
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph