Решение:
- Look at those clouds! It is going to rain. (Предсказание, основанное на наблюдении).
- Lulu has bought a ticket. She is going to travel to London next week. (План, намерение, подкрепленное действием - покупкой билета).
- I think Larry will make you a sandwich. (Предсказание, основанное на личном мнении, без явных признаков плана).
Ответ: is going to; is going to; will make.