—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
It has been announced that all the students ____ put on masks before going to school in case they are infected with SARS virus.
Pressed from his parents, and _____ that he has wasted too much time, the boy is determined to stop playing video games.
Lydia doesn’t feel like _____ abroad. Her parents are old.
A new study indicates that basic steps taken by people daily can go a long way in ____ the greenhouse gas emission.
—Did you call on any of your old friends when you returned to your hometown?—_______ of them. They were all very busy.