.—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
Look over there—there's a very long, winding path __________ up to the house.
The next thing he saw was smoke__________ from behind the house.【选项 】
The girl was so __________ of the snake that she began to cry the moment she saw it.
The driver couldn't react quickly enough when the road bent __________
Had early explores come from the southern hemi-sphere, would our maps appear __________ ?