The word "credible" means believable or true. The best choice is "sound" as it means true when it is used as an adjective. "Believe" is closely related to the word "credble" but cannot be the correct choice since "believe" is a verb while "credible" is an adjective. The other choices are unrelated. When none of the answer choices seem obviously correct to you, remember to consider their secondary definitions.

The correct answer is "precise." "Precise" and "accurate" are synonyms because both mean exact.  The other words do not mean "accurate."

The word "skeptical" means having doubt. "Suspicious" also means having doubt. Therefore, "suspicious" is the best choice, as "suspicious" and "skeptical" have the same definition. Considering the other choices, "sketch" means draw quickly, "true" means real, and "trite" means unoriginal.

The correct answer is "ridiculous."  "Absurd" and "ridiculous" both mean out of the ordinary or unusual, to the point of possibly being funny. The others words are all antonyms of "absurd."

"Credible" means believable or trustworthy. The best choice is "reliable" because it also means trustworthy. Considering the other choices, "doable" means able to be done, "sociable" means friendly, and "daring" means courageous. 

The word "dubious" means doubtful or untrustworthy. The best choice is "doubtful" because it is part of the definition of "dubious." Considering the other choices, "double" means two of something, "wrong" means not correct, and "hasty" means quick.

Obscure can be used as a verb or an adjective. As an adjective, it means hard to understand; as a verb, it means to hide. To further help you, reveal means to make known; display means to show; depict means to represent.

"Incoherent" describes someone or something that is unable to be understood.

"Persuasive" is an adjective that means good at convincing others to adopt your viewpoint. So, the answer choice closest in meaning to "persuasive" is "convincing," an adjective that means capable of causing someone to believe that something is true or real. None of the other answers are close in meaning to "persuasive": "weak" means lacking power; "false" means not true; and "extraordinary" means very unusual or remarkable.

If an object is "authentic," it actually is what it is supposed to be as opposed to fake. For example, if a dinosaur bone found at a dig site is found to be authentic, then it truly is a dinosaur bone and not a hoax. "Fraudulent" is clearly wrong, since it is synonymous with "fake" and therefore an antonym. "Striated" means striped and "flagrant" means conspicuous or bold, especially when referring to an offense; these words are also improper choices. Our final answer, the correct one, is "genuine," which means real or authentic.