患者女性，39岁，因龋损、松动拔除半年，要求义齿修复而就诊，口腔检查：缺失，缺隙大小约10mm，牙槽窝愈合良好，余留牙不松，咬合关系正常

若为该患者行固定义齿修复，下述哪一项是固定义齿修复的生理基础（）

A.基牙牙冠形态

B.颞颌关节

C.牙周潜力

D.牙龈

E.牙槽骨

Expressing gratitude is an important form of good manners. Nowadays more and more people in China have found it’ s high time to (16) a thankful heart for the young.

Everyone likes to get praised and appreciated. Gratitude is the greatest of virtues, which lets others smile and makes the world more beautiful. You just need several minutes to write down a thank-you note, but it brings much joy to the (17) .

We live in a society where we enjoy the different services of others. But (18) of them should be taken for granted.

Gratitude is also a kind of (19) in life. In developing gratitude for every moment--for the simple joys and even for the (20) times--we come to truly enjoy and appreciate life. Then we are able to see the (21) that surrounds us.

Try to write a thank-you letter to your parents for working hard to (22) you a happy life.

Be grateful to your teachers because of their (23) with your studies and character building.

Say thanks to your friends who (24) both your happiness and sorrow. We are sure it will bring them much joy and add (25) into your own life as well.

24（）

A.knew 

B.shared 

C.realized 

D.recognized