确定电力机车零件使用期限的方法有哪些？
参考答案：
常用方法有四种：
（1）运行实验法；
（2）调查统计法；
（3）实验室研究法；
（4）计算分析法。
A 34-year-old client is 34 weeks pregnant and is experiencing bleeding caused by placenta previ
a. The fetal heart sounds are normal and the client isn’t in labor. Which of the following nursing interventions should be of priorityA. Monitor the amount of vaginal blood loss.B. Allow the client to ambulate with assistance.C. Perform a vaginal examination to cheek for cervical dilation.D. Notify the physician for a fetal heart rate of 130 beats/minut
由美国最大的三家交易所CBOE、CBOT、CME组建的OneChiCago交易所主要从事（）的交易。
A.外汇期货
B.利率期货
C.股指期货
D.股票期货
