Anything

“Removing the test from its plastic case changes the test's exposure to air and humidity. Air and humidity affect the manner and rate at which the dye and chemicals cross the test. If you change the environment before the test is finished, you risk drying it out too quickly-- and when a test dries too quickly, the dye may dry in places it would not have otherwise-- making an evap line appear to be a positive result.”

Yes

Was the line there before you took it apart

I do too

Line was there before i took it apart i just wanted a closer look lol why does it become invailed if you take it apart

Invaild if you’ve taken it apart