She's got a lot on her mind. She had no choice but_______ her husband.
All passengers______go through safety check before they take a plane.
_____ carefully, Michael! There’s a school ahead.
Air pollution has become__________ than ever before. We must do something to stop it.
Old Mr. Black lives happily with his three dogs.of them are part of his family.
—can you finish the report on food safety? — In two days.