-_______ do you practice dancing every day?-For two hours.
________people, there ________for wildlife.
The Greens ______ in Paris and now they________ in China. They like China.
None of them knew what happened __________we told them about it.
The shopping mall will ________young people ________work.
---Look at the boy running on the playground. Is it David? ---It ______ be him. I saw him go to the teachers’ office just now.