A drinking straw can be used to draw liquids by following these steps:
Take the drinking straw and place one end into the liquid you wish to drink.
Hold the other end of the straw with your mouth, making sure that your lips create a tight seal around the end of the straw.
Using your mouth, suck the air out of the straw. This action creates a vacuum in the straw which in turn pulls liquid up through the straw and into your mouth.
It's important to note that the drinking straw should be inserted into the liquid to a depth that keeps the liquid level above the end in your mouth to avoid sucking in air bubbles.