range对象

Dim Row2 As Integer, Teacher As Byte, Row3 As Byte, RowC As Integer

RowC = 3 To Application.CountA(Range("a:a"))

For Teacher = 6 To 7

If Application.CountIf(Range(Cells(3, 6), Cells(RowC, 7)), Cells(RowC, Teacher)) = 1 Then

.Cells(2, 1) = Cells(RowC, Teacher)

这代码是什么意思？？
Application.CountA(Range("a:a")) 是什么？？
counta是什么意思？后面range(a;a),从A到A的一个区域？？

orange range Range Circles range.select out of range Sync.Out of Range signal out of range OUT OFF RANGE trfc out of range “range searching”怎么翻译？ at close range是什么意思