确诊前列腺癌最可靠的方法是
A.直肠指诊
B.经直肠超声
C.血PSA测定
D.针吸细胞学或穿刺活组织检查
E.MRI
参考答案:D
Unemployment can be divided into the following three categories:()
A. Frictional, seasonal, cyclical.
B. Structural, seasonal, technical.
C. Frictional, cyclical, structural.
离心式压缩机轴承温度升高的原因?