The answer to this is: <span>geriatrician </span>
Since you didn't give us the sentence 1, I can only assume.
A synonym is a word that has the same meaning as another word. So, the word <em>hard </em>can be synonymous with difficult, if it is a difficult task, or it can be solid, if the sentence is about rocks, or something like that.
The author most likely uses the word "scheme" to show the reader that Germany was a legitimate threat to the United States.
<span>"When you're the only sane person, you look like the only insane person"</span>
