—Look! The lights in the teachers’ office are still on. Is Mr. Li working?—No. It _______ be Mr. Li. I saw him leave just now.
--We’ll go to the Great Wall___ it is sunny tomorrow. --OK! Walking on the Great Wall must be great fun.
– Do you know how many _____ a horse has and how many _____ a bee has? --- Of course, I know.
Is it important us learn English well?
________ city would you like to live in, Beijing, Shanghai or Chongqing?
If you for your favorite TV programs, you will feel sleepy.