going straight up or down from a level surface or from top to bottom in a picture, etc. ซึ่งตั้งตรง

The vertical green security thread embedded into the banknote paper will change to the colour of red-purple when the user tilts the new banknotes.

Those crossed horizontal and vertical lines – the chequers or ``checks'' – belong entirely to the Brits.

Mr Nelson explained that vertical flying is ``basically doing a headstand'' in the air.

About the author

Writer: Terry Fredrickson
Position: Education Marketing and Support Manager