Correct Answer: B

Rationale: The correct word that should replace 'among' in the sentence is 'between' when referring to a distinction between two things. 'Among' is used when referring to more than two items or when the items are part of a group. In this context, 'between' is more appropriate as there are only two treatment protocols being compared.

Correct Answer: A

Rationale: In this sentence, 'lie' is the correct word for the patient wanting to recline on the bed, and 'lay' is the correct word for placing the tray of food on the table. Therefore, 'lie, lay' is the proper sequence of words for the actions described in the sentence. Choice B is incorrect because 'lie' should be used for reclining, not 'lay'. Choice C is incorrect as 'laid' is the past tense of 'lay,' not the present tense. Choice D is incorrect; 'lain' is the past participle of 'lie,' not the present tense.

Correct Answer: D

Rationale: The correct answer is 'which' as it correctly introduces a defining clause describing the style of hair Tracey wore. 'Which' is used to provide additional information about the noun 'French braid' and helps specify the particular style among others. 'Among' (choice A) is incorrect as it is used to show a relation of one thing to many others. 'It' (choice B) is incorrect as it does not serve as a relative pronoun to introduce a clause. 'That' (choice C) is incorrect as it is not the most suitable relative pronoun to introduce a non-restrictive clause in this context.

Correct Answer: B

Rationale: 'But' is the conjunction in this sentence. A conjunction is a word that connects clauses or sentences. In this case, 'but' links two contrasting ideas: the little girl wanting a cookie and her decision not to take one. The other options are not conjunctions; 'little' is an adjective, 'take' is a verb, and 'the' is a definite article.

Correct Answer: D

Rationale: 'Have to' is the correct choice as it fits the sentence structure. The sentence is in the past tense ('did we') and requires the infinitive form 'have to' to express the idea of necessity or obligation in the past. 'Has to' (Choice A) is incorrect as it is present tense, 'haven't' (Choice B) is a negative form and does not make sense in this context, and 'had to' (Choice C) would imply a past obligation that has already been fulfilled, which is not the intended meaning here.