Case of coordinative conjunction usage. 'Hardly' is always followed by 'when'.

“Turn up” is a phrase which means “to come” or “to disturb”. 'Turn down' means 'to reject (a request, advice, etc.)'. 'Turn over' means 'to change the position of, as by rolling'. Hence, option (2) is the correct answer.

The principal clause of the given sentence is in simple present tense and so the subordinate clause should also be in the same tense. And this condition is satisfied by option (2).

The opposite of “I will” is “won’t I”. Hence, (4) is the correct answer.

In cases like this, where we fail to turn our promises into a reality, conjunction 'but' is used.

“Went off” means “to finish up” and the given sentence depicts that the celebrations got finished very well. Hence, (4) is the correct answer.

“To fall out” is an idiom which means to quarrel and in this sentence ”out” is the best option to show that he has quarrelled with his partner. Hence, (4) is the correct answer.

“Cut down” is an idiom which means to reduce and is best used in terms of expenses as conveyed by the given sentence. 'Cut out' means 'to separate from other parts by cutting; to sever'. Hence, (2) is the correct answer.

“To break out” is an idiom which means “to start” and in the given sentence, we are talking about the starting of the World War in 1939. Hence, (3) is the correct answer.

“Interest” is always taken ”in” any activity and the same meaning is conveyed in the given sentence. Hence, (4) is the correct answer.

“To keep away” is an idiom which means “to remain absent” and in this sentence it is best conveyed by “away”. Hence, (3) is the correct answer.

“To give up” is an idiom which means “to leave” and this is the meaning which is conveyed by the given sentence. Hence, (2) is the correct answer.

“To go by” means “the act of passing by”. Hence, (3) is the correct answer.

“To introduce to” is an idiom which means “to be acquainted with” or “to get into acquaintance with”. This is conveyed that Joseph introduced me “to” his mother. So (1) is the correct answer.

The sentence before the blank conveys the meaning which clearly indicates the use of the auxiliary verb “can”. Hence (1) is the correct answer.

An objection has been raised in the sentence and a passive form is needed. Hence, (2) is the correct answer.

Some words like 'last', 'yesterday', 'this morning' etc take second form of the verb after themselves. “Rose” is the right word to show the rising of the sun in the past. Hence, (1) is the correct answer.

Whenever we refer to a specific point of time of the past, we use preposition since” for such references. Hence, (3) is the correct answer.

We are 'reconciled to' an idea, but 'reconciled with' a person. Hence, (4) is the correct answer.

“Lest” is always followed by “should”. Hence, (3) is the correct answer.

”Took off” means to leave the ground for a flight. Hence, (3) is the correct answer.

“Lest” is always used with “should”. So (3) is the correct answer.

'Playing off one community against the other' means 'using one community in opposition to the other'. And this is how the British continued their rule in  India. Hence, (2) is the correct answer.

“To live by” is an idiom which means 'to lead a life' and this is the meaning conveyed in the given sentence. Hence, (2) is the correct answer.

The sentence implies that only some works of reference are valuable and not all. ”A few” means ”some“, 'the few' means 'all', and 'few' means 'hardly any'. Hence, option (2) is the correct answer.