The benefits of good posture

stacked /stækt/ adjective
1. covered or filled with a large amount of things
The fridge is stacked with food.
fatigue /fəˈtiːg/ noun
1. [ U ] formal extreme tiredness
She was suffering from fatigue and a stress-related illness.
strengthen /ˈstreŋ.θ ə n/ verb
to make something stronger or more effective, or to become stronger or more effective
They have been strengthening their border defences in preparation for war.
flat /flæt/ adjective
level and smooth, with no curved, high, or hollow parts
An ice rink needs to be completely flat.
stationary /ˈsteɪ.ʃ ə n. ə r.i/ /-ʃə.ner-/ adjective
not moving, or not changing
a stationary car/train
The traffic got slower and slower until it was stationary.
ˈ eye ˌ level noun
If something is at eye level, it is positioned at approximately the same height as your eyes.
tilt /tɪlt/ verb
to (cause to) move into a sloping position
He tilted his chair backwards and put his feet up on his desk.
align /əˈlaɪn/ verb [ T ]
to put two or more things into a straight line
When you've aligned the notch on the gun with the target, fire!
impair /ɪmˈpeə r / /-ˈper/ verb
to spoil something or make it weaker so that it is less effective
A recurring knee injury may have impaired his chances of winning the tournament.

2. 
   THE ARCTIC VS THE ANTARCTIC
   

polar /ˈpəʊ.lə r / /ˈpoʊ.lɚ/ adjective
1. relating to the North or South Pole or the areas around them
the polar ice caps
hemisphere /ˈhem.ɪ.sfɪə r / /-sfɪr/ noun [ C ]
half of a sphere , especially the Earth
the northern hemisphere