All _____ can be done has already been done.
. I'm amazed that Mr Harris _________ have said nothing about the matter.
. — I will take my mid-term exam tomorrow. —_________.
. Look at the sign, Sir. We don’t permit _________ in the hall.
. — Do you know why the teacher asks for me? — He wants you to _________ your absence(缺席) last night.
. Sometimes she’d ask the driver to stop in front of a particular building and would sit _________ into the darkness, saying nothing.