Theory:

Meanings of difficult words:
  
Section - I
  
No
Words
Meanings
1
amusesprovide interesting, enjoyable occupation; entertain 
2
bifurcatesdivide into two branches or forks
3
concernedcared, worried
4
mergescombine to form a single entity
5
mightyhaving great strength, power
 
Section - II
  
No.
Words
Meanings
1
exhaustedvery tired
2
giddysensation of falling, dizzy
3
nauseateda feeling of sickness and vomiting
4
scorchingvery hot
5
sunburn
reddening, inflammation, even peeling of the
skin caused by overexposure to the ultraviolet
rays of the sun
6
sunscreen
a cream or lotion rubbed on to the skin to protect
 it from the sun
7
sunstroke
heatstroke brought about by excessive
exposure to the sun
8
street smart
knowledge necessary to deal with the
potential difficulties or dangers of life
in an urban environment
 
Section - III
 
No
Words
Meanings
1
antifreeze
a chemical added to water to reduce the
freezing point
2
automotiverelating to or concerned with motor vehicles
3
cabinet
a cupboard with shelves or drawers for storing
articles
4
cybersafesafe and responsible use of information online     
5
hazardousrisky, dangerous
6
social media
websites and applications that enable users to
create and share content online