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.

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.

The word "enlightening" comes from the word light, but it is used in a metaphorical sense. It means making something understandable. Think of when we say, "That was an enlightening explanation."It is like the explanation "shines" and makes its topic obvious. The best option for this is "informative," for informative things or actions help to explain something else.

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

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.

When someone is "ignorant," he or she does not know something. Thus, we can be "ignorant" of someone's name, meaning that we do not know it. Now, when we just say that someone is "ignorant" without any particular reason or explanation, we mean to say that the person is rather ill-informed. He or she is ignorant of things that he or she should know. Therefore, the best option that we have here is "uninformed." This can apply to both senses. None of the other options really express this idea of not knowing something.

When something is "planned out," we actively make sure that we think through the steps involved. "Intentional activity" is this kind of planned activity. Maybe you have heard something like, "He _un_intentionally bumped into the old man." This means that the person bumped into the old man without planning to do so. To do something intentionally is to plan it out before executing it.

Something that is "tentative" is unsure or uncertain. "Uncertain" is the best answer choice as it is a part of the definition of "tentative." "Certain" is an antonym of the word "tentative," and means sure or unavoidable; the other answer choices are unrelated.

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."

"Transient" is defined as lasting only for a short amount of time, making "temporary" the best answer choice. "Permanent," "long-term," and "lengthy" are all antonyms of transient.