辐射致癌的绝对危险（AR）是

a.In addition, no one knows whether the core is solid or not, since it cannot be directly observed.b.But since the Sun has no solid surface, it is hard to tell where the atmosphere ends and the main body of the Sun begins.c.Starting at the outside and going down into the Sun, the zones are the corona, chromosphere, photosphere, convection zone, and finally the core.d.Solar astronomers know that the Sun is divided into five layers or zones.e.The first three zones are regarded as the Sun’s atmosphere.The following sentences are from a paragraph, but they are in the wrong order.Choose the correct order from A, B, C, and D.______A、c-d-e-b-aB、d-b-a-c-eC、c-e-d-b-aD、d-c-e-b-a 点击查看答案

2011年版的《义务教育数学课程标准》规定义务教育阶段的数学课程性质具有（）（1）基础性（2）普及性（3）发展性（4）义务性

A、(1)、(2)、(3)
B、(1)、(2)、(4)
C、(1)、(3)、(4)
D、(2)、(3)、(4)

点击查看答案&解析