No matter what substance it may be, it is ________ atom.
—Do you think the thief entered through the back door? —No, if he had, I don’t believe he ______ the living-room window.
Go and join in the party. Leave______ to me to do the washing-up.
One of the rules is that under no circumstances _______to bring food, drink or chewing gum into the school.
After decades of effort, the city is still trying to _____ how to stop smoking in public places.
Lawmakers have approved the measures_____ protecting the personal information of Web users.