JOHN SPEAKS CHINESE FLUENTLY BECAUSE HE USED TO LIVE IN CHINA FO...

23. John speaks Chinese fluently because he used to live in China for ten years. A. Unless John had lived in China for ten years, he could have spoken Chinese fluently. B. If John hadn't lived in China for ten years, he could not speak Chinese fluently. C. Provided that John lived in China for ten years, he could speak Chinese fluently. D. Suppose John has lived in China for ten years, he can speak Chinese fluently.