Analysis:
The sentence describes an appearance or impression of someone enjoying themselves at a party. The structure 'seems + to be + verb-ing' or 'seems + to have' is used to describe current appearances or experiences. 'Seems to be having' indicates she appears to be currently enjoying the party.
Breakdown:
- A having: Incorrect. 'Seems having' is not grammatically correct.
- B to have: Incorrect. 'Seems to have a great time' is grammatically possible but 'seems to be having' is more common for an ongoing activity.
- C to be having: Correct. This structure 'seems to be + present participle' is used to describe an ongoing activity that appears to be happening.
Translated Question:
29 Она, кажется, ..... прекрасно проводит время на вечеринке.