Helen __________Gray ______ she left college.
—I don’t know if Dr. White _______ to the party next week? —I think he will come if he ________ free.
Shanghai is _______ one of the two cities.
Sixteen-year-olds shouldn’t be allowed to get their ears__________.
—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.
Dr. Green says that these children may find _______hard to think for themselves when they are older.