English

The correct preposition to complete the phrase 'What is the cause ___ the problem?' is 'of'. The phrase 'cause of the problem' is the standard and grammatically correct expression in English.

The correct future perfect tense is 'will have begun' to indicate that the play will start before he arrives. 'Would have begun' and 'would begun' are incorrect forms, and 'will begun' is grammatically wrong.

The word 'torture' means severe physical or mental pain inflicted on someone. The antonym is 'peace,' which means a state of tranquility or absence of pain and suffering, making option C the correct opposite.

The term 'Aborigines' specifically refers to the original inhabitants of a country, especially used in contexts like Australia. However, 'Natives' is a more general and widely accepted term for the original inhabitants of any country or region. 'Aborigines' is often considered specific to certain groups, such as the Indigenous peoples of Australia, and can sometimes be seen as outdated or offensive in some contexts. 'Citizens' refers to legal members of a country, and 'Primitive' is an outdated and inappropriate term. Therefore, the most accurate and general answer to the question 'Who are the original inhabitants of a country?' is 'Natives.'

A 'truce' is a temporary cessation of fighting, and 'armistice' specifically refers to an agreement to stop hostilities, making it the best synonym among the options. While 'agreement' and 'settlement' are related, they are broader terms and less precise in this context. 'Ratify' means to formally approve, which is not a synonym.

The word 'decimate' means to destroy a large portion of something, so 'Destroy' is the correct synonym. The other options do not convey the meaning of causing significant destruction.

Option C correctly preserves the original meaning and tense, clearly stating that the guest informed us in his last letter about his future arrival next week. It is grammatically correct and maintains the intended sense.

The correct preposition to use with 'good' when referring to a skill or ability is 'at'. Therefore, 'He is good at football.' is the correct sentence.

The word 'Gauche' means socially awkward or lacking grace, so its synonym is 'Awkward'. The other options have opposite or unrelated meanings.

The word 'dearth' means a scarcity or lack of something, so the synonym is 'Lack'. The other options do not convey the same meaning.

The word 'doleful' means expressing sorrow or sadness, so its synonym is 'Sad'. The other options do not convey the same meaning.

The word 'foster' means to encourage or promote the growth or development of something, which is synonymous with 'raise.' 'Increase' and 'lessen' do not capture the meaning accurately, and 'none' is not a synonym.

The correct preposition to use with 'the station' in this context is 'at' because it indicates a specific point or location. 'We arrived at the station an hour late' is the grammatically correct sentence.

The word 'wrath' means intense anger or rage, so the synonym 'Anger' is the most accurate choice among the options provided.

The word 'Intrepid' means fearless or bold. Among the options, 'Bold' is the correct synonym, while 'Timid', 'Affable', and 'Lazy' have different meanings.

The correct preposition to use in this context is 'from' because the phrase 'differs from' is the standard English expression to indicate a difference between two things.

The word 'mull' means to think about something deeply or carefully, making 'Think' the correct synonym among the options provided.

The antonym of 'selfish' is 'altruistic,' which means showing selfless concern for the well-being of others. The other options do not directly oppose 'selfish': 'helpful' is positive but not a direct antonym, 'egocentric' is similar in meaning to selfish, and 'acquisitive' relates to acquiring wealth or possessions.

The correct phrase is 'Despite the bad weather,' which means the outdoor party was rescheduled even though the weather was bad. 'Because of' indicates causation but does not fit well with the sentence structure here.

The word 'fervor' means intense and passionate feeling, which is closely synonymous with 'excitement'. The other options do not convey the same meaning.

The term "YOB" is British slang for a young troublemaker or hooligan, which aligns most closely with "Aggressive" among the given options. The other options do not relate to the meaning of "YOB."

The correct answer is 'Was' because the sentence requires the past continuous tense to describe an action happening simultaneously with 'I was sleeping.' 'She was playing the sitar' correctly matches this tense and subject-verb agreement.

The verb 'decide' is typically followed by the preposition 'on' when referring to making a choice about something. For example, 'They decided on the grey sofa' means they made a decision regarding the sofa. The preposition 'about' is not commonly used directly after 'decided' in this context. Therefore, the correct preposition to complete the sentence 'They decided _____ the grey sofa?' is 'on'.

The correct preposition to use with 'good' when referring to a skill or activity is 'at'. Therefore, 'I am good at tennis' is the correct phrase.

The word 'turmoil' means a state of great disturbance, confusion, or uncertainty. Among the options, 'Confusion' is the closest synonym, making option D correct.