Answer:
indicate a sudden change in thought
Explanation:
"The dash (–) is used to set off additional material within a sentence, often in order to emphasize it, to set off appositives that contain commas, or to indicate missing words."
Read the situations and write sentences as shown in the examples.
1. Jack is driving a car, but he's very nervous and not sure what to do.
<em>You ask : Have you driven a car before?
</em>
<em>He says : No, this is the first time I've driven a car.
</em>
2. Len is playing tennis. He's not very good, and he doesn't know the rules.
You ask : Have you played tennis before?
He says : No, this is the first time I've played tennis.
3. Sue is riding a horse. She doesn't look very confident or comfortable.
You ask : Have you ridden a horse before?
He says : No, this is the first time I've ridden a horse.
4. Maria is in London. She has just arrived, and it's very new for her.
You ask : Have you been in London before?
He says : No, this is the first time I've been in London.
The first one since it uses the Oxford comma.