血管性痴呆的诊断要点()
A.病程呈阶梯性进展
B.进行性痴呆
C.神经系统局灶损害体征
D.CT扫描为多发低密度灶
E.病前多有脑卒中病史
参考答案:A, C, D, E
________ the professor did all he could to help, the experience failed eventually.[ ]
A. Since
B. When
C. While
D. As
管道焊口位置应离开支吊架管部边缘()mm以上。
A、30
B、40
C、50
D、70