Question

1) William Shakespeare was born in 1564 in Stratford-upon-Avon. (2) It is a town in England. (3) He is believed to have attended the King’s New School there from age seven to age fourteen. (4) Teachers were strict in Shakespeare’s day. (5) The school day was long. (6) In the summer, school started at 6 a.m. (7) School did not end until 5 p.m. (8) In the winter, the school day was an hour or two shorter. (9) At age nine, students began learning Latin. (10) It was the language of international affairs. (11) In school, students spoke Latin. (12) Teachers also spoke Latin. (13) Students caught speaking English in school were punished.
Which is the most effective way to combine sentences (9) and (10)?
At age nine, students began learning Latin, and it was the language of international affairs.
Beginning to learn Latin at age nine because it was the language of international affairs.
Since age nine students began learning Latin, and it was the language of international affairs.
At age nine, students began learning Latin, which was the language of international affairs.

Answer 1

The answer is:

At age nine, students began learning Latin, which was the language of international affairs.  

Relative clauses provide additional information about something that has already been mentioned. In this case, the subordinate relative clause "which was the language of international affairs," makes a further comment about the previously mentioned Latin language.

Answer 2

At age nine, students began learning Latin, which was the language of international affairs