The correct answer should be <span>A. Bob twists his back to pick up the materials to feed his press machine. </span>
I will answer but I dont understand the question. Do you have a picture of it?
Answer: Avoid spilling of chemicals
Explanation:
The chemicals should be kept in air tight containers in order so that they cannot get spill over each other.
Cross contamination takes place when a different type of substance comes in contact with the different kind of substance.
The chemicals should be kept in a way that it does not comes in contact with the different one and get spoiled.
