— When shall we meet your cousin at the station?— His plane took off two hours ago, and it reach at 5 pm.
We couldn’t understand: what could ______ his sudden change of mind?
I didn’t mean to break your vase—it was just ______.
He was breathing ______ after the relay race.
People are concerned about the quality of the air they ______.
She walked home by herself, ______ she knew that it was dangerous.