Please help me to find the best choices for each sentences from my listed options:
American black bears in order to define their ………. and as a form of communication with other bears mark trees using their teeth and claws.
1) Territory
2) Domain
3) Realm
At the time of The Achaemenid Empire, the Persian empire had the largest ….. all over the world.
1) Territory
2) Domain
3) Realm --> I think in this sense it is used only in literary English.
This question can be answered in the …………. of psychology.
1) Territory
2) Domain --> I think in this sense it is used only in formal English.
3) Realm --> I think in this sense it is used only in written English.
In that web page, you can easily find all the new and ever-increasing discoveries in the …………. of medicine.
1) Territory
2) Domain --> I think in this sense it is used only in formal English.
3) Realm --> I think in this sense it is used only in written English.
We widened the ......... of our investigations, but as usual political issues limited us to do more.
1) Territory
2) Domain --> I think in this sense it is used only in formal English.
3) Realm --> I think in this sense it is used only in written English.
4) Scope
5) Range
6) Spectrum
PS. for me all the bold choices work for their related sentences and where I defined e.g. tow choice, I think both of the choices can be swapped together and mean exactly the same thing in that specific sense and at the same time, no one of the other choices work for that particular sentence. Anyway I would appreciate it if you could correct me if I make mistake.
Added:
In accordance with what has written in the Longman dictionary, I edited my question; here is my understanding from the dictionary and all the needed information (just based on the dictionary), but whereas I do not believe all the written points of a dictionary cannot always work, and whereas language changes, I brought all of the notes here to make it clear why I think only the bold choices work and the others do not work at all (or at least using them would make the sentence sound awkward and perhaps unidiomatic.)
Territory: 1) land that is owned or controlled by a particular country, ruler, or military force. 2) The area that an animal, bird etc regards as its own and will defend against other animals.
Domain: 1) Formal: An area of activity, interest, or knowledge, especially one that a particular person, organization etc deals with. 2) An area of land owned and controlled by one person or government, especially in the past.
Realm: 1) Written: a general area of knowledge, activity, or thought. 2) Literary: a country ruled by a king or queen.
Scope: The range of things that a subject, activity, book etc deals with.
Range: Spectrum: A complete range of opinions, people, situations etc, going from one extreme to its opposite.
