This book tells ______ life story of John Smith, who left ______ school and worked for a newspaper

at the age of 16. [ ]

A. the; /

B. a; the

C. the; the

D. a; /

下颌后部牙槽嵴骨吸收的方向为（）。

A.向下、向后

B.向下、向外

C.向下、向内

D.向后、向外

E.向下、向前