What have you done ____ my picture-book?
Being able to speak another language well is a great _____ when you're looking for a job.
―I think it’s too late to apologize to Kate.―Never mind. _______.
Having ________ every night is very important for your health.
He made three good friends in the university, ______ joined the army after graduation.
_______ is certain, people’s living conditions in China have improved a lot since the 1980s.