Correct Answer: C

Rationale: The correct answer is 'But.' In this sentence, the conjunction 'but' is used to show a contrast between the usual routine of taking a walk after breakfast and the fact that it was raining today. 'While' suggests a concurrent action, 'Because' implies causation, and 'When' introduces a time relationship, none of which are suitable in this context.

Correct Answer: D

Rationale: The comma after 'delicious' is unnecessary as it separates the adjective 'delicious' from the noun 'stew'. In this case, 'delicious' is describing the type of stew, so the comma should be removed to maintain correct sentence structure. The other commas in the sentence are correctly used to separate items in a list and after introductory phrases, making them necessary for clarity and grammatical correctness.

Correct Answer: C

Rationale: The prefix 'intra-' means 'within,' so 'intravenous' refers to something within veins. Choice A, 'Across veins,' is incorrect as 'intra-' does not indicate movement across but within. Choice B, 'Between veins,' is incorrect because 'intra-' does not imply a relationship between two separate veins. Choice D, 'Outside veins,' is incorrect as 'intra-' signifies something inside or within, not outside.

Correct Answer: C

Rationale: The key context clue essential to decipher the word 'ubiquitous' is the word 'now.' By comparing the rarity of automobiles a hundred years ago to their ubiquity now, the student can infer that 'ubiquitous' means something that is commonplace or found everywhere. Choice A ('Ago') refers to the past and does not provide information about the current state of cars. Choice B ('Cars') only contrasts rare and ubiquitous without indicating the change over time. Choice D ('Rare') simply contrasts with 'ubiquitous' without showing the transition from rarity to ubiquity.

Correct Answer: D

Rationale: The correct answer is sentence D: 'I cooked, so I could eat dinner.' This sentence uses a comma correctly to separate two independent clauses, 'I cooked,' and 'so I could eat dinner.' Choice A is incorrect as it lacks punctuation to separate the clauses properly. Choice B incorrectly uses a comma after 'so,' disrupting the flow of the sentence. Choice C incorrectly places a comma after 'I,' which is not needed in this context.