.The theory is true _______ the hotter a body is, the more energy it gives off.
They will fly to Washington, ______ they plan to stay for two or three days.
It isn’t quite ___ whether the Tibetan antelope is still being hunted.
---Where’s the little elephant? ---It’s said it ___ in the hospital.
She wondered what use she would _______ this chance.
_____ learn more knowledge, the students stay at school on Sunday.