可行经皮椎体成形术的疾病是（）.
A.椎体血管瘤
B.椎体感染
C.椎体转移瘤
D.骨质疏松症性椎体压缩性骨折
E.椎体结核
参考答案：A, C, D
生物体细胞内的核糖体有两种基本类型，原核细胞中的核糖体是（）核糖体，而真核细胞质中的是80S核糖体，线粒体内的核糖体是（）核糖体。
●Precedence Diagrammin gMethod(PDM) is a method used in activity sequencing.There are four types of dependencies or precedence relationships in PDM. The initiation of the successor activity depends upon the completion of the predecessor activity is called__(75)__.
A．Finish-to-Start
B．Finish-to-Finish
C．Start-to-Start
D．Start-to-Finish
