Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

The multitude of Middle Iranian languages and peoples indicate that great linguistic diversity must have existed among the ancient speakers of Iranian languages. Of that variety of languages/dialects, direct evidence of only two have survived. These are:
What characteristic of Middle Iranian civilization is shown by the number of different languages and their speakers?