128-129题共用备选答案
A．鞍式桥体&nBsp;
B．悬空式桥体&nBsp;
C．改良盖嵴式桥体&nBsp;
D．船底式桥体&nBsp;
E．盖嵴式桥体&nBsp;
128[单选题] 龈段呈凹形，不易清洁的桥体是&nBsp;
129[单选题] 食物可通过而不积聚的桥体是&nBsp;