—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
The two girls are so alike that strangers find ____ difficult to tell one from the other.
It ___ be the postman at the door. It’s only six o’clock.
She has already tried her best. Please don’t be too ____ about her job.
In the last few years thousands of films ____ all over the world.
Last month, the Japanese government expressed their thanks for the aid they ___ from China.