按谓词变元的不同，关系演算可分为元组关系演算和___________。
参考答案：域关系演算
有关糖尿病的诊断正确的是（）
A.空腹血糖不一定升高
B.所有患者都需行糖耐量试验诊断
C.尿糖检查一定阳性
D.三多一少症状是诊断糖尿病必须具备的条件
E.第一次测定静脉血浆血糖值>10mmol／L即可诊断
The Latin class had twenty students, most of which had had much better language training than I.
