编程时需注意的是要将声明语句写在同一行中

谁给的这个说法是错误的。
第一，简单变量声明，一行可以放多个，也可以一行一个。例如：
dim a as integer, b as integer, c as single,d as single
与
dim a as integer
dim b as integer
dim c as single
dim d as single
与
dim a as integer, b as integer
dim c as single,d as single
的效果完全相同。
其实简单得声明也可以一个变量写成两行三行的，但是没有必要。尽管如此，我还是给你举个例子：
dim _
a _
as _
integer
与
dim a as integer
是一样的效果，但阅读反而不方便，书写也麻烦。所以没人会这样做。

第二，api函数的声明一般比较长，放在一行阅读有困难时（或者为了其他自己喜欢的原因），也可以拆开成几行。例如圆弧绘制函数：
Declare Function Arc& Lib "gdi32" (ByVal hdc As Long, ByVal X1 As Long, ByVal Y1 As Long, ByVal X2 As Long, ByVal Y2 As Long, ByVal X3 As Long, ByVal Y3 As Long, ByVal X4 As Long, ByVal Y4 As Long)
也可以写成：
Declare Function Arc& Lib "gdi32" (ByVal hdc As Long,_
ByVal X1 As Long, ByVal Y1 As Long,_
ByVal X2 As Long, ByVal Y2 As Long,_
ByVal X3 As Long, ByVal Y3 As Long,_
ByVal X4 As Long, ByVal Y4 A