Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The electromagnetic fields under, on and up Earth surface as earthquakes
  precursor in the Balkans and Black Sea regions   It is demonstrate that the analysis of accuracy measurement of geomagnetic
field and the behavior of local tide gravitational potential can serve as an
earthquake precursor

21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
19
The categories of this paper are: eess
28
The categories of this paper are: alg-geom
22
The categories of this paper are: chao-dyn
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
33
The categories of this paper are: plasm-ph