—How long have you known the doctor ? — he helped me three years ago.
English _____________ in more and more countries today.
— I didn’t see you at Kangkang’s birthday party. — I didn’t go because I _____ .
Zhengzhou will be more and more convenient when Zhengzhou Subway_____ in two years.
Food safety is important. Rules must ________ stop people from food pollution.
Our headmaster isn’t in his office. I can’t find him anywhere. Did you notice him ______ the office?