Teachers required that all the students ___ their homework all alone.     

－ What does the sign over there say?－ “No person ____________ bring drinks into the student computer pool.”

“Is there a flight to London this evening?” “There _______ be. I’ll phone the airport and find it out.”

 Maybe if I ________ science，and not literature then，I would be able to give you more help.(2011·北京)

She had a talent for paintings and art, but her parents recommended that she______ literature .