The key here is to note that the groups had been meeting separately, though once a year would come together. Although the other words might fit, the best sense will be the one that captures this sense of coming together most closely. To be “plenary” is to be a meeting including all of the groups at a given event. It means something like full session, a meaning that could be guessed from the root “plen-,” which means full. Related words are “plenty” and “plenitude.” 

All that we can tell about Nestor is that he will sample any religion whatsoever. Let us not, therefore, go so far as to imply that he has no religion. The sense is best captured by “latitudinarian,” which means merely to show no preference (generally in religion). It is related to words like “latitude,” implying breadth or freedom for expression.

The key here to note is the contrariety implied in the “while . . .” subordinate clause. If it is often abstract, the spirit of a civilization is at least concrete in the laws. To be concrete could be said to be “like something” in the sense of some thing. The word “res” in Latin means thing and is related to “real” and “republic,” which means the public things. The “-fy” is a standard ending meaning to do or to make, and is likewise found in forms like “-fact-” (factor), “-fic-” (artificer), -“-fect” (perfect), or even “-fication” (amplification).   

Although John might likewise be called an excellent friend, he certainly was unwavering (at least from the description). The word “stalwart” implies this loyalty.

The key words to note are “quantifiable” and, more importantly, “regular measurement.” The word “metrical” means related to measurement and is used in many words such as “symmetric” (one thing measuring directly with—sym—another) and “econometrics” (the study of economics by statistics and other mathematical / empirical methods).

The key thing to note here are the number of terms involved. A “couplet” (like a “couple”) has only two members in it.  If something is “ternary,” it has three parts, like the “triad” (three part structure): “being, life, and intellect.”

The key word here is “health,” which is best matched by “insalubrious,” which means unhealthful. Something that is “salubrious” is healthful. The word is related to the simpler Latin root “salus,” meaning health, prosperity, or [even] greeting. It is related to English words like “salvation” and “salutation.” 

Although you might be tempted to choose “health,” we can surmise more accurately that the old man had kidney problems—hence the need for a kidney transplant, though certainly this is itself a type of health issue. The adjective “renal” means pertaining to the kidneys. It is found in the word “adrenaline,” now called “epinephrine,” because the “adrenal” glands are on the kidneys: ad + renal.

The thing to be noted here is the contrast between the outer muscle and the inner muscle.  Now, a number of the words are meant to tempt you into this simple form of reasoning, but you must always choose the best word. Since we are considering a heart attack specifically, the kind of muscle involved (in the heart) is “cardiac.” When someone has a “cardiac arrest,” that person’s heart has stopped its regular beating and no longer effectively delivers blood.

Since the argument was haphazard, the conclusions would seem very unlikely in their final claims. To be “dubitable” is to be “doubtful.” It comes from the Latin word for “doubt.” The latter (“doubt”) is close to “dubitable” in English form, but other related words are “indubitably” and “dubious.”