Answer
As far as i know contact lenses pose no threat to your eyes unless you keep them poorly cleaned.
Explanation:
The answer is Stomach
this digestive acid is usually called gastric acids.The gastric acids in our body is powerful enough to destroy a metal.
This process is happening before the digested foods enter the small intestine
The answer is tighten and contract.
In order for the students to pull the rope their muscles will need to tighten and contract so they are able to continuously pull with all their strength and power. Relaxed or twitched muscles will result in release of the rope.
