Answer:
1. I may not be able to jog today, as I am feeling a bit under the weather.
2. At the start of the lecture, the new professor tried to break the ice by telling a joke.
3. I will be on cloud nine when my articles get published.
Explanation:
When someone says they are feeling under the weather, it means they are not feeling well.
When someone says to break the ice, it means to get a conversation going or to relieve the tension in a social setting.
When someone says they are on cloud nine, it means they are super happy.