Everyone knows that ______ paper was invented by _______ Chinese.
You need to have______if you want to teach the group of naughty children well.
Don't worry. I'm sure things will get better .
Tom was about to close the window ________ his attention was caught by a bird.
With so many noises from the busy traffic in the street, I couldn’t______ and do my research work.
You _______ here last week if you were really worried about your work.