—Will you see to _____ that all the papers should be handed in after class? —All right.
Though it was in the midnight, ________ there were a lot of people in the street.
The ground isn't wet. It ________ have rained last night.
We tried to find a table for seven, but they were all _______.
In winter, it is dangerous to go to school with snow ______the ground.
_______ late you are, we will wait for you to come to have dinner.