Everyone knows that ______ paper was invented by _______ Chinese.
Mr. Smith couldn’t open the door because his naughty boy ______ it from the inside.
We’re advised not to leave the water ______ after using it.
She ______ have attended that meeting, for she was doing paperwork in the office then.
I know little about the accident because not much ______ about it up to now.
______ the task in time, we had to work late into the night.