Lately some scientists are experimenting ___________ white mice to ____________ this kind of medicine.
—— May I leave the office before 5 o’clock in the afternoon? —— No, I’m afraid you_______.
He seldom listens to others. He_____answer for what he has done.
—— Don’t forget to bring my new books tomorrow afternoon. —— No, I_______.
Wei Hua told me that Wu Dong was_______ill.
Shall we meet at 5:00? Let’s make it ______earlier?