The population problem may be ___ one of the world today.
I don’t like ________you speak to her.
Hurry up, or the tickets ________out by the time we get there.
As we came to the work site, the workers were seen _______the new house.
. The reason for all the changes being made _______to us yet.
24. You ought to have put the milk in the refrigerator, and now ________sour.