21. This interesting book tells ________ life story of John Smith, who left ________ school and worked for a newspaper at the age of 16.
A. a; / B. a; the C. the; the D. the; /
22. ________ is known to all, the moon travels round the earth once every month.
A. It B. As C. That D. Which
A. whom B. where C. which D. while
