In this task the focus is on physical knowledge about the world. Given the provided goal task in the input, describe a process that would lead to the asked outcome. This process often involves physical motions with objects, such as moving them, arranging them in a certain way, mixing them, shaking them, etc. 

To brighten clothes without using bleach.
Add a pinch of salt to your load of laundry.

Use the sun and a magnifying glass to start a fire.
On a sunny day, hold the glass above something that will burn easily.  Use a dry leaf of a piece of paper.  Move the glass so the suns rays focus on the paper.

Can I change the color of my blood

No, your blood can only be red or blue