Q.3 When the Principal entered the class, a student on the blackboard.​

When the Principal entered the class, a student on the blackboard.

Explanation:-

The given sentence is in past continuous tense.

The past continuous tense, also referred to as the past progressive tense, is used to express actions at a particular moment in the past. The action started before that moment but has not finished at that moment.

It is composed of two parts : the past tense of the verb "to be" (was/were), and the base of the main verb "+ing".

word choice -uses unfamiliar words such as husbandman instead farmer

tone - has the tone of a biography and is more of a narrative than an informational text

sentence structure - long sentences with multiple ideas that reflect the fashion of speaking in Victorian England

writer’s attitude toward the subject - writer shows great knowledge about the development of astronomy and great admiration for the astronomers mentioned in the work

how the writing reflects the writer's period versus how it might come across to modern readers -

use of formal language reflecting the more formal customs of the time; words such as protracted, illumined, verisimilitude, sagacity not likely to be used in a modern equivalent like Carl Sagan’s Cosmos

text difficult to read for many modern readers because of long-winded sentences and unfamiliar words