Fill in the Blanks

Verb 'committed' is always followed by preposition 'to'. 'Committed to' means 'to agree to something; to promise or pledge to do something'.

Case of phrasal preposition. 'To look after' means 'to take care of'.

Case of idiomatic usage. 'To put up with something' means 'to tolerate'.  

Case of idiomatic usage. 'Taking a glance at something' means 'to take a quick peek at someone or something'.

The correct preposition to use with the adjective enamoured is of. One is enamoured of something or someone, meaning they are filled with a feeling of love or admiration for it.

'Concerned about' is a phrasal preposition that means 'worried for'.

Verb 'enter' shows the change of periphery of the subject/object. 'Enter' is always followed by preposition 'into'.

Case of idiomatic usage. 'Blow up' means 'to destroy someone or something by explosion'. 'Blow up' means 'to put out (a fire or flame) by blowing'.  

Case of idiomatic usage. 'Bring forward' means 'to introduce someone or something'. 'Bring forth' means 'to give birth to'.

Case of idiomatic usage. 'Break into' means 'to enter a place by using force'. 

Case of idiomatic usage. 'At large' means 'free; uncaptured (usually said of criminals not in custody)'.

Case of adjectival usage. The building mentioned here is a noun. To qualify this noun, we need an adjective. 'Habitable' is an adjective that means 'can be inhabited; fit to be lived in'.   

The sentence describes a contradiction: people who want mercy from others are often not merciful themselves. 'Paradoxical' fits the first blank, and 'clemency' (mercy) fits the second.

The internet offers vast choices with very few restrictions. 'Unlimited' and 'minimal' correctly complete the sentence.

The phrase 'in principle' is the correct idiomatic expression meaning in theory. 'Principal' refers to a person in charge or a main sum of money.