λ（t）称为（）。
A.故障率
B.故障密度
C.密度函数
D.故障因素
参考答案：A
将一些与企业核心业务关联性不强的业务交给专业公司来操作的方式称为( )。
A．租赁 B．借用 C．征收 D．外包
Many companies give away small quantities of their produce as samples ______ people can try them
before buying them. [ ]
A. if
B. because
C. so that
D. since
