下列选项中，( )不属于工程技术方面的风险因素。
A．自然条件 B．分包 C．工程变更 D．技术规范
参考答案：B
Studies show that Americans chat on their phones for more than five hours a month, _____ Europeans.
A．as much as twice
B．twice as much as
C．as much twice as
D．as twice much as
下列哪类人群不属于艾滋病感染的高危人群（）
A.同性恋者
B.静脉药物依赖者
C.性乱交者
D.静脉吸毒者
E.医护人员
