English

The correct preposition is 'between' because it is used when referring to something in the middle of two items, in this case, the mug and the pen.

The term "infallible" means incapable of making mistakes or being wrong, so it refers to someone free from mistakes and failures. Option C correctly captures this meaning.

The correct preposition to use with 'protested' when indicating the reason for the protest is 'against'. Hence, 'The students protested against the ill-treatment of their leader' is correct.

The idiom "apple-pie order" means something is in perfect order, neat and tidy. Therefore, option A, "Neat & tidy," correctly defines the phrase.

The correct preposition to indicate the instrument used to cut the finger is 'with'. 'He cut his finger with the knife' is grammatically correct and idiomatic.

A 'hamlet' is a small settlement smaller than a village, making it the correct answer. 'Aviary' is a place for keeping birds, and 'apiary' is a place where bees are kept, so they are unrelated to the size of a community.

The word 'abrupt' means sudden or unexpected. Among the options, 'Sudden' is the correct synonym, while 'Noisy' and 'Calm' have different meanings, and 'All of these' is incorrect.

The correct preposition to use with 'serious' followed by a gerund (verb in -ing form) is 'about'. The phrase should be 'He is serious about visiting Islamabad.' None of the options A (Of), B (For), or C (To) are correct in this context. Since 'about' is not provided as an option, the question as given is flawed. However, among the given options, none is correct, but the closest correct preposition in standard English usage is 'about'. Therefore, the question should be corrected to include 'about' as an option, and the correct answer should be 'about'. Since 'about' is not an option, the best course is to correct the question by adding 'about' as an option and marking it as the correct answer.

The antonym of 'attract' is 'repel' because 'attract' means to draw towards, while 'repel' means to drive away or push back. The other options do not convey the opposite meaning of 'attract'.

The correct preposition to use with 'turns' in this context is 'to'. The phrase 'he always turns to you' is idiomatic and grammatically correct, meaning he directs his attention or reaction toward you. The option 'at' is incorrect here. This is supported by standard English usage and grammar references on prepositions.