No, Romeo and Juliet is written from the third person omniscient point of view. Sorry if this was wrong! Have a great day :)
The sentence in which the underlined verb is used correctly in the subjunctive mood is the one that reads "if I were you, I would try out for the lead in the school play".
In the English language, the subjunctive mood is used to talk about conditional or imaginary situations. In this case, it has been used to explore a condition which is contrary to fact, that is, the person speaking is not the addressee. That is why the sentence reads "if i were you". It is a piece of advise.
If you're asking for main idea, the main idea or thesis statement sentence is sentence 1, where they explain what the passage is about.
Answer: Derive
Explanation:
In this sentence the incorrect verb is derives and the correct one is derive.
Derive is considering transitional verb and the meaning of it is, for example, to receive or to take something from some source which in this case is correct since in sentence we have that something is derived from the source, in this case, hand-operated devices and other.