Correct Answer: D

Rationale: The correct answer is 'Having.' In the sentence 'I am looking forward to having my birthday party next week,' 'having' is the correct present participle form of the verb 'have' to indicate an anticipated event. Choice A 'Going' is incorrect as it does not match the structure of the sentence. Choice B 'Go' is incorrect as it is the base form of the verb and does not fit grammatically. Choice C 'Have' is incorrect as it is the base form and does not convey the future action in the sentence.

Correct Answer: A

Rationale: The correct answer is 'Were.' In the subjunctive mood, we use 'were' for hypothetical or unreal situations. The sentence should read, 'If I were you, I'd leave now.' Choice B ('Is') is incorrect because it is not in the subjunctive form. Choice C ('Be') is incorrect as it is the base form and not the correct form for the subjunctive mood. Choice D ('Was') is incorrect as it is the past tense form and not used in the subjunctive mood.

Correct Answer: A

Rationale: The correct answer is A: 'Is.' In this sentence, 'Economics' is being treated as a singular subject, so the verb should also be singular. 'Is' is the correct singular form of the verb to agree with the singular subject 'Economics.' Choice B, 'Been,' is incorrect because it is the past participle form of the verb 'be' and does not agree with the singular subject 'Economics.' Choice C, 'Am,' is incorrect because it is the first-person singular form of the verb 'be' and does not agree with the singular subject 'Economics.' Choice D, 'Are,' is incorrect because it is the plural form of the verb 'be' and does not agree with the singular subject 'Economics.'

Correct Answer: A

Rationale: The correct contraction for 'will not' is 'won't'. 'Willn't' (Choice B) is not a standard contraction in English. 'Wouldn't' (Choice C) is the contraction for 'would not,' not 'will not.' 'Will'nt' (Choice D) is not a recognized contraction in English. Therefore, 'won't' is the correct choice as the contraction for 'will not.'

Correct Answer: D

Rationale: 'Themselves' is the correct reflexive pronoun to use when referring to 'children' in the plural form. The other options, 'themself,' 'theirself,' and 'theirselves' are not grammatically correct as they do not match the plural subject 'children.'