— What should we do to prevent the flu?—We should keep our rooms_____ and the air fresh all the time.A. cleaning B. cleaned C. clean
I often go to sleep ________10:00 p.m. ________7:00 a.m..
—Could you pass me the book? —______________.
Most students hope _______well in their study.
Half of the books ________easy for the students to read.
The cat climbs into the sitting-room _______the open window.