患者，男，30岁，缺失，间隙较小，可摘义齿修复，不能排成品牙，可雕刻蜡牙。的形态特点是（）

A.颊面外形类似上颌尖牙的唇面

B.颊面中央有颊嵴

C.舌面比颊面小得多，最突处在颈1／3处

D.面为四边形，近缘嵴＜远缘嵴

E.中央窝内有二点隙和中央沟

--- Can you lend me the book Gone with the Wind?

--- Sorry, I returned it to the library just now. Maybe it is  still ____.

A．available

B．affordable

C．acceptable

D．valuable