English

The sentence 'The baby has lost her doll' is in the present perfect tense. The correct passive voice form is 'Her doll has been lost by the baby,' which maintains the present perfect tense and correctly uses the passive structure.

The preposition 'for' is used to indicate a duration of time, which fits the sentence 'He has been living in Switzerland for two years.' 'Since' is used with a specific starting point in time, which is not given here.

English speakers commonly use the present continuous tense (subject + 'be' + verb-ing) to talk about future arrangements that have already been planned or decided. In the sentence 'I _______ New Zealand next year,' the present continuous 'am going' correctly expresses a planned future event. Option D 'am going to' is incomplete without a following verb and thus ungrammatical in this context. Options A and B are less appropriate for expressing a definite planned future arrangement here.

The word 'slap' means to hit someone or something with an open hand, so 'Hit' is the correct synonym among the options provided.

The word 'ruse' means a trick or a cunning plan, which is synonymous with 'ploy'. The other options do not share this meaning.

The correct preposition to indicate proximity in this context is 'by'. 'She is standing by her brother' means she is standing close to him. Other options do not fit the context appropriately.

The word 'serene' means calm, peaceful, and untroubled. The antonym is 'anxious,' which means worried or uneasy, making option D the correct opposite.

The word 'handful' commonly means a small number or amount that can be held in one hand, making 'Small number' the correct synonym among the options.

The correct preposition to use with 'bound' in this context is 'to,' making the phrase 'bound to the stake.' This is a standard and idiomatic usage in English to indicate that someone is tied or fastened to a particular object or place. Other options such as 'of,' 'with,' or 'at' do not fit idiomatically in this phrase.

The sentence is in the passive voice, requiring the past participle form of the verb 'steal,' which is 'stolen.' Therefore, 'The ring was stolen by thieves.' is correct.