It ________ be the postman at the door.It's only six o'clock.
Do you mind if I _____ with my work while you are getting tea ready.
I shall be in china for three weeks. Can you make some suggestions _____ what I should see?
_____ is known to us all is that America is a developed country _____ the First World.
Hidden _____ by a big tree, his house was not to be seen.
_________ is known to all,good friends _________ happiness and value to life.