Why do we need protect Polar bears?

fast

n. [intransitive] ​to eat little or no food for a period of time, especially for religious or medical reasons

- Muslims fast during Ramadan.
- Patients usually fast overnight before undergoing surgery.

cast/shed/throw light on something

to make a problem, etc. easier to understand

Recent research has thrown new light on the causes of the disease.

deliberate

synonym intentional, planned antonym unintentional	done on purpose rather than by accident	The speech was a deliberate attempt to embarrass the government.
	​(of a movement or an action) done slowly and carefully	She spoke in a slow and deliberate way.

adj.

manipulate v.

manipulate sb/sth manipulate sb into sth/into doing sth

to control or influence somebody/something, often in a dishonest way so that they do not realize it

She uses her charm to manipulate people. - As a politician, he knows how to manipulate public opinion. - They managed to manipulate us into agreeing to help.

verb.

platform

(American) track	at train station: the raised flat area next to the track at a train station where you get on or off the train	(British English) What platform does it go from?
synonym: rostrum	for performers: a flat surface raised above the level of the ground or floor, used by public speakers or performers so that the audience can see them	Coming onto the platform now is tonight's conductor, Jane Glover.

n.

determine

[transitive] synonym establish determine sth	to discover the facts about something; to calculate something exactly	An inquiry was set up to determine the cause of the accident.
[transitive] determining factors Age and experience will be determining factors in our choice of candidate.	to make something happen in a particular way or be of a particular type	- Upbringing plays an important part in determining a person's character. - The physical capabilities of a plant determine where it can and cannot live.
[transitive] determine something determine (that)	to officially decide and/or arrange something	- A date for the meeting has yet to be determined. - The court determined (that) the defendant should pay the legal costs.
[transitive, intransitive] - determine to do something - determine on something - determine (that)…	to decide definitely to do something	- They determined to start early. - The government determined on a change of policy. - From that moment, I determined that it should not happen again.

v.

degree

/dɪˈɡriː/

[countable, uncountable] - degree of something - with a degree of something - to a degree

the amount or level of something

- Her job demands a high degree of skill. - The story has been staged several times before, with varying degrees of success. - I agree with you to a certain degree. - To what degree can parents be held responsible for a child's behaviour? - Most pop music is influenced, to a greater or lesser degree, by the blues.

n.

remodel sth

v. to change the structure or shape of something

- The interior of the building has been completely remodelled.
- They put forward plans to remodel the education system.

undergo sth

v. to experience something, especially a change or something unpleasant

- My mother underwent major surgery last year.
- Some children undergo a complete transformation when they become teenagers.

maternity

n. /məˈtɜːrnəti/ [uncountable] the state of being or becoming a mother

- maternity clothes (= clothes for women who are pregnant)

- a maternity ward/hospital (= one where women go to give birth to their babies)"

den

n. [countable]

for animals: the home of some animals
room: a room in a house or apartment, used for activities not involving work:	The kids are watching TV in the den.
for children: a rough structure, usually built outside from pieces of wood, cardboard, etc., in which children play
crime: a place where people secretly plan or take part in dishonest or illegal activities:	a drug/drinking/vice den
a baby of wild animals	A mother bear is fiercely protective of her cubs.

cub

n. /kʌb/ [C] a baby of wild animals

• A mother bear is fiercely protective of her cubs.

deplete

v.

/dɪˈpliːt/

[transitive, usually passive, intransitive] (formal) deplete (sth)

to reduce something by a large amount so that there is not enough left; to be reduced by a large amount

Food supplies were severely depleted.

paradox

n.

/ˈpærədɑːks/

a situation or statement that seems impossible or is difficult to understand because it contains two opposite facts or characteristics:

It's a curious paradox that drinking a lot of water can often make you feel thirsty.

hibernate

v. /ˈhaɪbərneɪt/ [intransitive]

to spend the winter in a state like deep sleep

breakthrough

n.

/ˈbreɪkθruː/

an important development that may lead to an agreement or achievement

This particular technique had been presented by the surgeon to the media as a breakthrough in treatment for the condition

majestic

adj.

/məˈdʒestɪk/

impressive because of size or beauty

The college is close to Edinburgh’s majestic castle.

agile

adj.

/ˈædʒl/

synonym nimble noun AGILITY

able to move quickly and easily

a strong and agile athlete

mutation

n.

/mjuːˈteɪʃn/

a change in the form or structure of something

This essay examines the mutation of ethnic politics into nationalist politics.