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: C

Rationale: In alphabetical order, 'Assemble, assembly, assembling, assembled' is correct. The alphabetical order is determined by the first letter of each word. The correct sequence starts with 'Assemble,' followed by 'assembly,' then 'assembling,' and finally 'assembled.' Choice A, B, and D do not follow the correct alphabetical order as the words are not arranged alphabetically.

Correct Answer: C

Rationale: The correct answer is 'C: Laid.' 'Laid' is the correct past tense form of 'lay,' which means to put something down. 'Layed' in choice A is incorrect as the past tense of 'lay' is 'laid,' not 'layed.' Choice B, 'Drop,' is incorrect as it does not fit the context of placing something on the table. Choice D, 'Lay,' is the base form of the verb and does not fit the sentence in the past tense.

Correct Answer: B

Rationale: The correct contraction for 'They are' is 'They're.' 'Their' is a possessive pronoun indicating ownership, not a contraction. 'The're' is not a valid contraction. 'No contraction used' is incorrect as there is a contraction for 'They are,' which is 'They're.'

Correct Answer: D

Rationale: The correct answer is D, 'There.' In this context, 'There' is incorrect as it should be replaced with 'their' to show possession, referring to the uniforms belonging to the team. 'Their' (choice A) is used correctly to indicate possession. 'Going' (choice B) and 'They're' (choice C) are also used correctly in the sentence.