Her expression suggested that she ___ happy.
Earth Day is celebration of life and our planet. It is a reminder that we need to________the world we live in and that we should learn to respect life and nature.
There isn't much money left. We must ________our spending.
I ________back the money.
He hurried to the booking office, only________that all the tickets had been sold out.
She ________a chain to the dog's collar.