Part 1. Definition
You are given a passage. Using the information present in the passage, you need to classify it into one of the 10 topics: 0 - 'Society & Culture', 1 - 'Science & Mathematics', 2 - 'Health', 3 - 'Education & Reference', 4 - 'Computers & Internet', 5 - 'Sports', 6 - 'Business & Finance', 7 - 'Entertainment & Music', 8 - 'Family & Relationships', 9 - 'Politics & Government'.
Part 2. Example
Optical mice use an LED and a camera to rapidly
capture images of the surface beneath the mouse.
The infomation from the camera is analyzed by a
DSP (Digital Signal Processor) and used to detect
imperfections in the underlying surface and
determine motion. Some materials, such as glass,
mirrors or other very shiny, uniform surfaces
interfere with the ability of the DSP to
accurately analyze the surface beneath the mouse.

Since glass is transparent and very uniform, the
mouse is unable to pick up enough imperfections in
the underlying surface to determine motion.
Mirrored surfaces are also a problem, since they
constantly reflect back the same image, causing
the DSP not to recognize motion properly. When the
system is unable to see surface changes associated
with movement, the mouse will not work properly.
Answer: 4
Explanation: The passage talks about optical mice or mouse throughout which is a part of computer system. Thus, it is correctly classified to "Computers & Internet"
Part 3. Exercise
The Earth is round because it is a large body, and gravity tends to make large bodies round because that is the gravitational efficient configuration for the matter to be in.

There are a few reasons you can encounter non-round bodies in space:

1) the object is small (for example asteroids), so it's gravity has less say proportionally on the shape

2) It has experienced a catastrophic collision with a large body

3) It is under very strong rotational or tidal forces

4) It is expelling matter/energy in the form of cosmic jets, nova ejecta, etc.
Answer:
1