The best guide for answering this sentence is the expression “easily overlooked,” though the remark about “immediate evidence” is also helpful. When something is easily overlook and not evident with blinding immediacy, it can be said to be “subtle,” meaning that it is either indirect or even (more properly) fine / delicate. Something very “fine” or “subtle” is something small—i.e. not large, blatant, and obvious.

Since the expression “raging irately” is used in the participial clause, the best option will be the word that is as strong as this expression. The word “tempestuous” indicates such a strong temperament, better than the much weaker “disagreeable” and “unfriendly.” The word “tempestuous” literally means “like a storm,” as can be seen in its obvious relation to the word “tempest.”

Although one might say that the state was going to watch the questionable group, the contrast in this sentence is really with “persecution.” In opposition to that, it would be best to choose “tolerant,” for when one tolerates a group, he or she allows it to exist, even if it seems questionable or even undesirable. The sentence does not speak directly about surveillance and therefore does not merit the choosing of “vigilant,” “aware,” or “watchful.”

Since the sentence directly mentions star charting, the best answer will be that which describes the data as being related to heavenly bodies or stars. Therefore, the two “astro-” options should stand out immediately. Here, you must be careful not to confuse the two words. Astrology is concerned not with the science of measuring (etc) stars but with the so-claimed “meaning” of stars in the sense of horoscopes and things of that sort. It is astronomy that studies the scientific laws of the stars. This is indicated by the “-nomy” at the end of the word, which is derived from Greek word for “law.” It is found in the word “autonomy,” literally meaning “having a self-given law.”

The key words to note are “musical” and “flowing.” The best description of the teacher’s voice will reflect these two parallel descriptions. Probably the most tempting trap answer is “fluent,” which means “flowing.” However, “lilting” better matches the two descriptions mentioned. A lilting sound is one that rises and falls in a pleasant manner. When applied to a voice, it means that it has such a gentle rising and falling. Although it does not directly mean “musical and flowing,” it does, by extension, imply a certain musicality and gentle flow to the voice. In any case, it is much better than “fluent,” which generally is used to describe one’s ability to speak well (often in another language) and only secondarily is used for the more general sense of “to flow;” thus, lilting fits more closely.

The key word here is “opposition.” Although the group was suppressed, we do not know anything about its legality. Therefore, the best option is “dissident,” which means “disagreeing” (with someone else). The word literally means “to sit apart from.” The “sitting” portion is reflected in “-sident” and “dis-” portion means “apart from” or “opposed to.”   Do not be fooled by “dissonant,” which means “a clashing sound.”

The key thing to note is that the sentence describes the dog’s ability to smell, not merely to breathe. Therefore, the options “pulmonary” (relating to the lungs), “inhalation,” and “breathing” are all inadequate. The word “olfactory” means “related to the sense of smell.” The “olfactory system” is comprised of the sense organs and nervous system components related to the sense of smell. It comes from the Latin for “to smell.”

The word rigorous can mean “thorough” but it can likewise mean “demanding.” The other options for this sentence to express difficulty in the course but likewise imply additional content like “tiring” or “being to much” (e.g. overwhelming). The word “rigorous” comes from the Latin for “stiffness” and here means “demanding” in the sense of being “stiff and unbending” in the pursuit of a goal.

The contrast here is between effect and cause, that is between things “coming after” and things “coming before” an event. Since our sentence does not speak of specific kinds of causes or even their regularity, the best adjective will be one that merely expresses the fact that causes “come before” a given event. The word “antecede” literally means “going before.” The prefix “ante” means “before” and is found in the English “antechamber,” meaning a small room that is “before” another room (and in which people are often first received as guests). Also, it is found in “antebellum” which literally means “before the war” and is often used to describe the southern United States before the American Civil War.

Since the sentence speaks neither of effeminacy nor of cowardliness, the best option is “maudlin.” The word means “sentimental” with the negative sense being “self-pitying” and perhaps induced by drunkenness. This negative implication suffices for this sentence, for it implies that the old man judged such displays in a negative light.