Solution:
- RUN
Shelly tries to run every day. She doesn't mind when the weather is good but she refuses when it's cold and wet. - EAT
Nick's mum makes him eat cabbage even though he hates it. She forces him to eat bananas, which he doesn't like, and even though he can't stand seafood, she cooks fish every Friday. - BUY
Irene could buy the trainers if she had more money, but she can't afford to buy them at the moment. The sales assistant in the shop advised her to buy them next month because they will probably be cheaper then.
Answer: 1-refuses, 2-eat, 3-buy.