He's read this book before, ______?A. hasn't he B. doesn't he C. isn't he
—How long has Kangkang _____from home?—For five days.
—I have never visited the Great Wall.—_____.
There are ninety teachers in our school. _____ of them are men.
—_____ the population of the U.S.A. in 2005? —It _____ about 296 million. A. What is; is B. What was; was C. How many is; was D. How many was; is
—Does your father still smoke?—No, he has succeeded in _____smoking for three years.