Group of vet students in a class and the lecture say to them, it...

Group of vet students in a class and the lecture say to them, it is critically important that watch carefully what I do and do exactly the same

So with this dead cow on the floor, the lecture sticks a finger in the cows bum then lick a finger then says he wants each to do the same.

Reluctantly each student goes up to the cow, sticks a finger in it's bum and licks.

Once all had done that the lecture says, this is why I say it is critically important that watch carefully what I do and do exactly the same. If you had done so you would have noticed I stuck my middle finger in the cows bum and licked my index finger