You can't predict everything.Often things don't as you expect.
—Who______ it be that is knocking at the door?—It ______ be Father, but I’m not sure.
—Your mother becomes more and more forgetful. —Yes. She searched for her cell phone for a whole day last Sunday but it ______ in her coat pocket the next day.
_______ of food is in need nowadays in Africa.
I’m really tired _______ Tom. He had me _________ for two hours in the rain.
If you cheat in the exam, you could hardly _________ it.