The teacher ___ the students not to ___ quickly when answering questions.
The US is about the same size as China, but its population is five times ____.
The number 5.12 is a special number, ______I think, that will be remembered by the Chinese forever.
—When did you come back? —An hour ago. Youthe computer games.
As _______ unemployment is very high at the moment, it’s very difficult for people to find _______ work.
—Would you mind if I closed the window? —______. It’s that cold outside.