A Cat Tongue-Twister

See if you can do this. Read it out loud, as fast as possible without mistakes.

(It’s supposedly one of Dr. Seuss’s lost tongue twisters. Yeah, right!)

This is this cat
This is is cat
This is how cat
This is to cat
This is keep cat
This is a cat
This is sucker cat
This is busy cat
This is for cat
This is forty cat
This is seconds cat

Now go back and read the THIRD word, in each line from the start.