In winter, we must pay attention to _________.
The chance will be given to only ________ students, so ________ of you should try hard to catch it.
The food in the fridge _________ bad. Throw it away, please.
--- You should be careful when ________.--- Yes, I will. I’d like to know when ________ to have a rest.
I prefer ________ at home ________ some reading to ________ shopping.
It’s selfish ________ him ________ the cakes with others.