Answer: At age nine, students began learning Latin, which was the language of international affairs.
Step-by-step explanation:
- By using a relative pronoun 'which', sentences 9 and 10 are connected into one. Relative pronouns are used to give additional information about a noun (Latin in this case).
- The first sentence 'At age nine, students began learning Latin' (which is independent) is, in this way, joined to a subordinate clause 'which was the language of international affairs.' The two sentences form a new, complex sentence.
- This is the most natural way to connect the two sentences.