### plotting in a script file

I have install sage in my computer and i have started testing sage examples. I dont understand sth. for example

sage: v = [(1,10),(2,20)]
sage: line(v)

it runs in shell and I can look plot screen.
I try below codes

sage: load "test.sage"

or

But instead of Interactive Shell, when I try to run the file "test.sage",
on terminal :

$ sage test.sage

it isnt right.