What __________the population of China? One-third of the population__________workers here.

A．is; are

B．are; are

C．is; is

D．are; is

下列事件过程的功能是：建立一个名为Datal的随机文件，存放角度值及这些角度的正弦函数值和余弦函数值，角度为1，2，3，…，90。请在空白处填入适当的内容，将程序补充完整。
Private Type Ang
　K As Integer
　Sinx As Single
　Cosx As Single
End Type
Dim Ksc As Ang
Private Sub Form Click()
Dim Y As Single
　Open ______
　Y=3.14159/180
　For i=1 To 90
　　Ksc.K=i
　　Ksc.Sinx=Sin(i*Y)
　　Ksc.Cosx：Cos(i*Y)
　　______
　Next i
　Close #2
End Sub