欧洲流经国家最多的国际性河流是[ ]
A.多瑙河
B.莱茵河
C.鲁尔河
D.塞纳河
答案:A
下述哪项政策属于健康促进公共政策
A.环境保护法B.公共场所禁止吸烟规定C.A+BD.传染病防治法E.B+C
The average age at which people begin to need eyeglasses vary considerably.
A.varies
B.is varied
C.will vary
D.has been varied