The sense of the word to be chosen must express the notion of being “crucial,” “central,” or something of the like. The word “cardinal” comes from the Latin for “hinge” (as in “door hinge”). Something is cardinal when everything else “hinges” on its success or ability.

In comparison with his friends’ opinions of his argument, Adam thinks that he has given solid reasoning that does not only rely up on the emotive and stylistic force of the words used (as would be the case in a rhetorical argument).  Although such solid reasoning would lucidly present the conclusions, the very style of rigorous reasoning is best called “demonstrative,” a word clearly related to the verb “to demonstrate,” coming from the root meaning “to show.”  It is related to the word “remonstrate,” meaning “to protest forcefully.”  Likewise, it is related to the Roman Catholic liturgical instrument called a “monstrance,” which is used to “show” the communion for devotional exercises.

The key expression in this sentence is the one stating that Gina “feared being caught.”  Since she fears detection, she would want to “sneak” out of bed.  Someone acting furtively is acting in such a way as not to be noticed.  The word comes from the Latin for “theft,” though the English word merely needs to imply that one does not desire to be caught (for fear of some repercussion—real or imagined).

Based on the description provided, one could say that Joseph was an “outgoing” person. If someone is “extroverted,” they are literally said to be “turned outward” in the sense of being engaged with the world in an active manner.  The word comes from the prefix “extra-”, which means “outside of” and a stem that is derived from several Latin words for “to turn.”  The latter can be found in English words like “convert,” “introvert,” “versatile,” and “inversion.”

The contrast in this sentence is between matters internal and external to the state.  The word “domestic” is derived from Latin roots for “home” found in words like “domicile” and “domesticate.”  The word has an extended meaning when applied to political affairs, indicating that certain classes of actions and undertakings are related to matters “at home” as opposed to those that are “abroad.”

Someone with “plenipotentiary” authority is authorized to act on behalf of a nation (or any other person / group / etc) in any fashion whatsoever.  Such a person is said to have “full authority,” a meaning that comes out in the literal meanings of the parts of the word.  “Pleni-” is derived from the Latin “plenus” meaning “full” or “complete” and is found in English words like “plenty” and “plenitude.”  The second half (“-potentiary”) comes from roots meaning “power” or “ability” and is related to words like “potency,” “impotent,” and “potential.”

Cognate words are ones that share the same lineage, such as the word “fenestra” in English (meaning “an opening in bandage or an opening made in the midst of a surgery”) and the French “fenêtre” (meaning “window”) are both derived from the Latin “fenestra,” (meaning opening for light or a window).  The word “cognate” literally means “of the same birth” or “with+born.”  The “co[g]-” prefix means “with” (like “cohabitate” or “coordinate”).  The “-[g]nate-” portion is derived from Latin roots related to birth.  Similar English words are “nativity,” “natal,” and “nascent.”

The key word to note is “arboreal” which indicates that the scenery in the hometown has something of a “tree-like” character (or, more likely, is filled with many trees).  Nothing is said about the seclusion of the area, and “pastoral” above all implies fields.  The word “sylvan” comes from the Latin “silva” for forest. 

The clues in this sentence indicate that George was a “preachy” type of person.  Such a person could be called “predicatory,” a rather uncommon word, but one with roots that you can perhaps see.  It really is a combination of “pre” and “dicactory.”  The prefix here means “before” in the sense of being “before (=in front of) the crowd.”  The later is related to words like “diction,” “contradict,” and “dictionary.”  Together the word makes an adjective describing one who speaks in front of a crowd.  

The implied contrast in this sentence is not merely a matter of expecting one personality type and unexpectedly finding another.  Although that is certainly true, the boy’s mother is shocked at the character of the criminal activities.  In contrast with an innocent and upright childhood, these activities would not only be unexpected but also “nefarious,” meaning “wicked” or “criminal.”