I was as sick as a dog.
The term "divers" in the passage likely refers to a variety or a range of different types or kinds. It is an older usage of the word, meaning "various" or "several," and often denotes diversity in the subjects being discussed. Without additional context, it might imply that there are multiple distinct elements or categories involved in the situation described.
It is the first sentence of a paragraph which is the topic sentence.
It in symmetry with sentence a is what? What is a sentence with symmetry in it? This sentence with symmetry is symmetry with sentence this.
Who or what the sentence is about is the subject of the sentence.
Who or what the sentence is about is the subject of the sentence.
The subject of a sentence is who or what that sentence is about.
yes
A simple sentence is a sentence with one clause expressing a single thought. This sentence is a simple sentence. This sentence, though similar to the first, is not a simple sentence.
compound sentence, simple sentence, and complex sentence
a descriptive sentence is a sentence that describes something in one sentence
As a question, it can be a sentence, like: A sentence can have one word, and as a question then it can be a sentence: Who?
This is a sentence. A prisoner has to serve the sentence the judge gives him.