为什么我已经setwd了，可是read.table就是报错。我getwd（），显示的路径没问题，可是路径里面的txt文件就是读取不出来。有哪位老师可以解答一下吗？

read.table("abc.txt")
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") : cannot open file 'abc.txt': No such file or directory
> getwd()
[1] "D:/rtemp"
> read.table("D:/rtemp/abc.txt")
Error in file(file, "rt") : cannot open the connection
In addition: Warning message:
In file(file, "rt") :
  cannot open file 'D:/rtemp/abc.txt': No such file or directory
>