Catherine's mother doesn’t allow her to go anywhere outside the town ________ another member of the family is along.

A．without

B．if

C．unless

D．with

承包商管理人员和一般技工的知识、经验和能力风险属于（）。

A．组织风险

B．经济与管理风险

C．工程环境风险

D．技术风险